Presenting Archaeoacoustics Results Using Multimedia and VR Technologies

1 Introduction

This study explores the use of multimedia interactive technologies to present music archaeology, sound archaeology, and in particular archaeoacoustics results, addressing the advantages of virtual reality (VR) headsets over other flatscreen interactive technologies. In the Soundgate series of apps, three archaeological sites are interactively modelled visually and with audio, a series of five caves in Spain featuring Palaeolithic paintings, Stonehenge in the United Kingdom, and Paphos Theatre in Cyprus. These sites were chosen because of their cultural significance as World Heritage Sites, because they show progression of human culture, an increasing level of human manipulation of space enclosed by stone, as well as contrasting acoustic environments.

Detailed metrical analytical results of acoustic study of these three sites have been discussed in a separate paper (Till, 2019). Acoustic metrics, such as early decay time, reverberation time, speech transmission index, clarity, and bass response, empirically describe the acoustics present. An acoustics expert may be able to read a table of such acoustic metrics and gain from it some understanding of sonically what it would be like to be in the space. In a cross-disciplinary study such as this, in order to allow archaeologists, musicians, and wider audiences to gain an intersubjective understanding of how these spaces were perceived in the past, it is useful to use digital modelling to afford a phenomenological experience of the space and its acoustics.

In a number of bundled apps, Unreal Engine (Epic Games, n.d.) is used to present the acoustics of archaeological spaces in an interactive format, integrated with digital 3D graphical models. Unreal is a computer game engine, containing a set of creative tools for creating interactive virtual environments. One can import a range of graphical assets, as well as sounds, and add programming that controls the way the user interacts with them. A number of different technical approaches were used in the apps, including photogrammetry, reconstruction based on laser scans of a contemporary site, archaeological digital 3D graphical modelling reconstruction based on site plans, adding impulse responses captured on site to studio recordings, digital acoustic modelling, and audio recordings made on site.

The study begins by addressing a number of theoretical perspectives, including use of interactive technologies, affordance, ecological approaches, phenomenology, context, intersubjectivity, and flux of experience. Discussion of post-processual multi-sensory archaeology that embraces uncertainty and embodiment is discussed alongside actor–network theory (ANT) and non-representational theories (NRT). These concepts are defined and discussed. This section is followed by an introduction to the archaeological sites. The development of interactive models of each site is examined, each requiring different approaches, and the implementation of audio rich soundscapes featuring musical performances in modelled interactive acoustics is discussed. The implementation of these models in an interactive app is explored, followed by details of the use of VR headset technology to improve users’ immersion, flow, and sense of presence. The study is concluded with discussion of results and conclusions.

2 Theoretical Approach

An ecological approach to sonic perception suggests a relationship with set and setting, an experience of sound mediated by the (mind)set of the person listening, and the setting in which the sound is heard (Clarke, 2005; Clarke & Clarke, 2011). An ecological approach is adopted in this study, exploring the affordances present in a context, those things that are unveiled as possibilities or likelihoods, as well as those that are clearly shown by the data available to be not possible or certainties. From an ecological perspective, an analysis of the acoustics of an archaeological site that is carried out purely quantitatively by generating a set of standard acoustical metrics is a limited approach in that it has an incomplete ability to tell us about wider experiential perception, and about the contextual meaning of the acoustic ecology present. Archaeoacoustics is an interdisciplinary field that includes the arts as well as the sciences, an arts-led approach complimenting quantitative metrical approaches, and assisting in addressing the complexities of interpretation of the ancient past. The arts offer an embracing of interpretation and even speculation, helping the construction of hypotheses based on affordances and known data, and contributing to empirical testing of those hypotheses.

It is important in this context to be clear about when speculative interpretations are being suggested, and the level of certainty present. Unless one has no interest in exploring issues of meaning in addition to description, some level of speculation is inevitable as one studies increasingly distant time frames. In scientific language speculation is termed creation of hypotheses or consideration of possibilities, and is a part of all experimentation. It is important that empirical evidence is collected to attempt to prove or discount such ideas, and to be clear about the level of supporting evidence present. Computer modelling creates hypothetical reconstructions of archaeological sites, and interactive exploration of these models can help to engage with different possibilities experientially, including assessment of acoustic factors.

A number of terminologies are relevant to archaeoacoustics, a field that uses acoustic methods (British Standards Institute, 2009; Long, 2014) to study archaeological sites (Scarre & Lawson, 2006). These include music archaeology, from where archaeoacoustics emerged; sound archaeology, which combines music archaeology and archaeoacoustics (Till, 2014); and sound studies, a parent field that includes a range of broader research into sound (Till, 2020). When considering immersive, interactive and VR technologies and taking an ecological approach, the term acoustic ecology is useful, a term coined by Schafer (1977), which addresses musical as well as non-musical sounds, including elements of the surrounding soundscape such as background, nature, or animal sounds. Such elements are important in virtual environments, as they immerse the user in a sense of the external natural world. Acoustic ecology has been preferred to the term soundscape (Ouzounian, 2017; Paine, 2017) for its focus on inclusivity and engagement, and an understanding of the variability of perception of an ever-moving acoustic ecology, rather than the static place of the soundscape.

As Schutz (1932) tells us, how we interpret meaning is experientially mediated, and depends upon how the meaning of an action to an actor is placed contextually. If our experience of the acoustics of an archaeological site consists only of a number-filled table on a static piece of paper, this experience is stranded in a disembodied state outside of time and space. A metrical approach is highly valuable to researchers, as it is effective in constructing an objective intellectual understanding of data related to those acoustics, but provides an incomplete understanding. Although the present study focuses on interactive audio-visual modelling, it is suggested that experiential approaches are complementary methods to metrical approaches (Till, 2017).

Places are contextualised spaces (Cresswell, 2004; Tuan, 1977); meanings and traditions give space a sense of place. Interactive digital audio-visual modelling allows the actor not just to explore ancient spaces, but to virtually explore historic places in order to create a reconstituted imagined past, a construction that is a fusion of past architecture and contemporary experience. It is intended in the apps discussed in this study that the users construct their own understanding of the use of the site in the past, inspired by their experience in this virtual world. This approach suggests that an understanding of the past is a construct unique to one’s own perspective, rather than an authentic processual knowledge (Hodder, 1984) of something that might be considered absolutely correct or true.

While this approach can provide an insight that can help form an understanding of the past, it is clearly not an experience of the past itself, and the audience is trusted to navigate that distinction, taking a culturally optimistic stance (Laurent, 2016). Our own experience of time and space is likely to be very different from that of our ancestors. However, sound can help us to try tuning-in to what Schutz (1932) calls the flux of experience of the past. Someone else’s flux of experience in inner time may differ from our own, and the tuning-in that Schutz describes is to a quasi-simultaneity to the acoustic ecology of the ancient past, time flexing from distortions generated in the mix of a contemporary digital context, and an artistic re-enchantment of an ancient ritual site.

In order to take into account setting and context in a phenomenological sense, this study uses audio-visual and interactive digital technologies, such as computer game engines, apps, and VR, to afford an experience of the acoustics of an archaeological site for a user. The intention is to create a post-processual phenomenology that allows the individual user to carry out their own virtual examination by interactively exploring a space visually and sonically, expanding this activity beyond the professional archaeologist, and embracing the understandings of a wider user group. This is in order to understand how their individual experience relates to the curated experiences that are constructed within these apps, which draw upon inspiration from the past. While many other archaeological sites have been modelled interactively (see for example Dylla et al., 2009; Frischer 2011; Frischer et al., 2002; Haydar et al., 2011; Helling et al., 2004), they have almost never included modelled acoustics or accurate environmental soundscapes, instead either being silent or using atmospheric or cinematic music and sound.

The intertextuality on display in these apps is contributed by many human sources: a group of prehistoric participants dispersed across thousands of years, who noticed within a cave its sonic and visual ecologies, and marked it as special by paintings and other visual motifs; the communities who built Stonehenge over many hundreds of years; the designers and makers of Paphos theatre, who together sculpted it’s sonic and architectural character; digital modellers who worked on models of the sites involved; the programmers of the interactive and acoustic modelling software used; archaeologists who informed the work; and musicians recorded while performing at these sites. Schutz focuses his phenomenological theories on activities that bring different actors together, whether human or contextual, and similarly the intention is that these apps focus on how human beings meet the other as a “We” (Kersten, 1976). This study explores approaching the “We” through what Becker (2004) calls Deep Listening, hearing a sonic situation by listening with one’s whole body, as a phenomenological and embodied experience.

This research aims to allow an exploration of intersubjectivity. In this instance, this term is used to relate to individuals’ instinctive understandings of the spaces under study, as well as the connections between the understandings of individual users. Most importantly, it addresses an attempt at connections between understandings of the original occupiers of the spaces in the past, and those who explore the models of the spaces virtually in the present. Although the minds of other contributors and participants are screened off when exploring these virtual spaces on an app or in an audio-visual installation or VR headset, the user interacts with the distant subjectivities of ancient users of the modelled spaces. Since these virtual worlds have been experienced by hundreds of thousands of people, online or through the European Music Archaeology Project (2015, 2018) exhibition, further intersubjectivity is generated by individuals’ responses, and discussions of their experiences. It is accepted that an intersubjective phenomenology that attempts to explore the presence of the past (Sheldrake, 2011) is limited, problematic, cannot be proven, and should not be presented as the whole story; it is rather an interesting and potentially informative activity in and of itself, that can contribute something different, whether to an archaeological understanding of the contexts being studied, an understanding of the activities that may have taken place in the spaces, or an understanding of ourselves.

Such an intersubjective approach is contentious and much discussed (Barua & Das, 2014; Cornejo, 2008; Desjarlais & Jason Throop, 2011; Oliver, 1998). As an example, “in our opinion, such disagreement between the goal and the evaluation of VR applications in Archaeology is due to an implicit assumption that visual realism, immersion, and navigation are sufficient to simulate the past, and constitute a universal didactic method” (Pujol-Tost, 2019). This publication suggests that VR is being used to create a trip through time to simulate the past. I argue rather that the audience is aware that they are not travelling in time, that they know enough of VR to understand it is a modern experience, but that some level of connection to the past can occur, producing an experience that provides some level of understanding of the experiences of our historical predecessors. The suggestion is that an incomplete understanding that may have some inaccuracies is preferable to not trying for fear of error. This study proposes that such VR work is valid as long as one respects the limits of the understandings produced, states them clearly, and acknowledges uncertainty. Uncertainty is a significant part of academic study, as is the potential for failure, and although this form of study has some level of risk of inaccuracy, it also has potential for understandings that are not otherwise possible.

The appropriateness of the application of phenomenology to archaeoacoustics is underlined by the influence of phenomenology on the field of architecture. Architectural phenomenology explores how dwellings and dwelling interact with the earth, the sky, mortality and death, and the divine and divinities; that is it goes beyond a functional approach to architecture as the design of buildings, to explore humanitiy’s relationships to buildings, and to the activities that go on within them (El-Bizri, 2011). This perspective is particularly relevant in the caves under study, and at Stonehenge, both of which operate as a kind of axis mundi, a cultural archetype of a space that acts as a nexus between different perceptions of existence. Phenomenology’s accepted usefulness within architecture suggests that it has a role to play in archaeoacoustics and archaeology.

Phenomenology has had a mixed reception within archaeology. It offers an approach to further the understandings of past lives, but risks accusations of subjectivity. Hamilton et al. (2006) discussed these issues and suggested using phenomenology to complement more traditional approaches, a suggestion implemented here through the existing publication of acoustic metrical data (Till, 2019) before exploring a phenomenological approach.

This study exists within a multi-sensory archaeological frame (Day, 2013), moving beyond a frozen stratigraphic view of archaeology and its resultant visual focus. Phenomenology has found a new home in recent years in digitally focused archaeology research. In this case, phenomenological approaches are used to present data that have been generated using scientific methods. Set within what Hodder and Hutson (2003) discuss as a post-processual approach, multiple readings and interpretations are sought and accepted, affording audiences the opportunity to explore, in the present, experiences of the presence of the past, to be their own masters of reality, adopting an ecological approach. The differences between the contemporary users of this research, the past cultures that inhabited these archaeological sites, and the action of modern sensitivities, interests, context, and prior experiences are not ignored or dismissed, but the focus is rather on what can be learned through a fused perceptual act of looking and listening (Ingold, 2000, p. 245). Much as in the ANT of Latour (2005), this approach examines the agency of both human and non-human actors (acoustics, design, and architecture) in the construction of a network, in this case, an acoustic ecology. It is influenced by, rather than adopting, an ANT set of methods, but as in ANT, proving intentionality is not a primary focus, nor is it assumed in this case, in terms of whether the acoustic effects present were intentionally created or as is often the case, a byproduct of architectural construction or natural structures.

A range of theoretical ideas have been discussed because of the cross-disciplinary nature of this research, which has emerged from a musical and artistic origin, but has also involved archaeological and acoustical fields. A methodological frame that allows the integration of these disparate ideas is that of the post-structuralist non-representational theories (NRTs) of Dewsbury (2003) and Thrift (2007). They point out that to gain understanding of areas of culture, where physical activities and direct experience have a key role to play, there is a need for engagement with embodied practices, rather than solely focusing on binary oppositions or cultural theory. NRTs often involve the fusing together of separate methodologies, such as in this case drawing from acoustics, music, and archaeology; they valorise direct experiences, and are sympathetic to phenomenological approaches. The audio-visual artworks created here are presented as NRTs created from the fusion of a range of ideas. These NRTs address a number of specific research questions. How does one study the experience of the acoustical ecologies of these (and other) archaeological sites? How can one present the results of archaeoacoustic studies in a manner that aids interpretation and enhances understanding? What can be learned from a sound-led and audio-visual study of the soundworlds of these three different archaeological sites?

Archaeology is based on empirical methods and scientific approaches, but also embraces interpretation and speculation on possible theories, just as other scientific fields posit hypotheses. Within archaeology, scholars are often interested in gaining a better understanding of the lives of the people who used a space. Exploring issues relating to meaning, belief, ritual, or cosmology often requires a mixture of quantitative and qualitative methods, as well as empiricism, interpretation, and even imagination. The worlds of the past are highly alien to our contemporary existence and mind-set. While it is important to avoid pseudo-science, or assertions without evidence, it is equally valuable to remain open-minded to approaches that differ from standard methods. While conventional empirical scientific approaches are excellent for describing what is happening, the apps described subsequently intend to reach beyond description in order to explore understandings of meaning and perception. Such issues become further complicated when considering dissemination of results to different audiences. As this project originates from a primarily artistic perspective, the research described here considers the needs of a public audience as a significant priority, another reason why it uses multimedia and interactive technologies to explore the acoustics of these sites.

3 The Sites

The apps focus on three archaeological case studies: Palaeolithic painted caves in northern Spain, Stonehenge in England, and Paphos Theatre in Cyprus. The caves are part of the Cave of Altamira and Palaeolithic Cave Art of Northern Spain UNESCO World Heritage Site, a large group of caves that feature ancient paintings and engravings. The caves modelled in Cantabria are El Castillo, Las Chimeneas, La Pasiega, and La Garma, along with Tito Bustillo in Asturias. They were selected by Dr Roberto Ontañón (Director of the History and Archaeology Museum, Santander) to represent a range of different contexts. Stonehenge is a well-known Neolithic stone circle in Southern England, and also a World Heritage Site. Various phases of the site’s development are examined acoustically. Paphos Theatre in Cyprus, or the Hellenistic-Roman theatre of Nea Paphos, was built around 300 BC, and was used until around 365 AD. It had seating for 8000 spectators and is again a World Heritage Site (Till, 2019).

The caves studied feature both paintings from as long as 40000 before present (BP), and a tradition of decoration with visual motifs that continues until the end of the Magdalenian period, 12000 BP (Pike et al., 2012). The Songs of the Caves multi-disciplinary AHRC/EPSRC funded Heritage Science Research Development Project (SOTC) was set out to study their acoustics, and is discussed in two existing publications (Fazenda et al., 2017; Till 2014), and on a project website (Till, 2012). These publications provide contextual information about the caves, the acoustic methodology used, and results. SOTC was inspired by the work of Reznikoff and Dauvois (1988), who hypothesised that the positioning of cave art was related to the acoustics present at a particular position. Reznikoff (2006) explored a number of caves in France and elsewhere, observing modal resonance and variation in reverberation, which he suggests was what inspired the creators of cave paintings. His methodology did not include statistical study, providing indicative evidence and a suggested hypothesis rather than conclusive empirical results. SOTC captured more than 200 impulse responses in the caves, either next to Palaeolithic paintings or engravings, or in control positions with no visual motifs. Details of archaeological context were recorded in each position, and logistic regression analysis was used to examine whether there were statistical relationships between acoustical and archaeological features. The study found a statistical association:

between acoustic response and the positions of Palaeolithic visual motifs … in these caves. Our primary conclusion is that there is statistical, although weak, evidence, for an association between acoustic responses measured within these caves and the placement of motifs. We found a statistical association between the position of motifs, particularly dots and lines, and places with low frequency resonances and moderate reverberation. (Fazenda et al., 2017, p. 1347)

SOTC indicated that acoustics were in some way linked to the caves’ better-known tradition of visual motif-making. The earliest known human musical instruments are also found in Palaeolithic caves, such as the Hohle Fels and Isturitz vulture bone flute-like pipes that date from 40–30000 BC (Conard, Malina, & Munzel, 2009); a range of evidence suggests that sound played an important role in the ritual life evidenced by the cave art in this period (Pasalodos Jiménez, da Rosa, & Diaz-Andreu, 2021).

Stonehenge is a Neolithic monument in southern England. Parker Pearson and his team (Parker Pearson, 2012; Willis et al., 2016) describe the site as a place of, or for, the dead, and the site and its surrounds contain a number of significant burials. It was used in prehistory for ritual activities that are related to the winter solstice in particular, and is also the site of modern solstice celebrations in summer and winter. Darvill (2006) suggests that Stonehenge was related to healing. In many cultures, rituals relating to healing, astronomy, ancestor worship, or the dead are related, and many such rituals use sound and music as a key element (Rouget, 1985). Research on the acoustics of Stonehenge was inspired by a pilot study by Aaron Watson (2006), which showed that there were acoustic effects at the present-day monument. My previous publications (Till, 2009, 2011) analysed the structure of the final complete arrangement of the site, and field studies with acoustics researcher Fazenda (2013) analyzed a full-size concrete Stonehenge model in the United States, that has an approximately similar design. This research identified a powerful low frequency resonance as well as a small amount of reverberation and echo (Till, 2010), something which was also described by author Thomas Hardy in his novel Tess of the D’Urbavilles.

The Acoustics of Greek and Roman theatres have been explored as part of the ERATO project (Rindel, 2011), and in a range of publications (Farnetani, Prodi, Fausti, & Pompol, 2004; Gade, Lisa, Lynge Christensen, & Rindel, 2004; Kang & Chourmouzuadou, 2008). Kang’s use of raytracing-based acoustic modelling software Odeon informed the acoustic modelling in the apps described in this study. The writings of (Maconie 2005) and the development of theatres, Odea and other performance venues, show that there is an understanding in Roman culture that architectural design can influence the acoustics of a space; there is evidence of an appreciation of acoustics, and of attempts to intentionally control them. This is evident in the Paphos Theatre in Cyprus, the most recent site modelled in the apps, a site with sophisticated acoustics and a clear delineation between audience and performers.

The apps developed in this project provide evidence to support the hypothesis that the acoustic ecologies of human ritual culture evidence in these sites developed over time, from an appreciation of the acoustics of natural spaces such as caves to human-generated acoustics, in buildings such as Stonehenge that were created for ritual purposes, perhaps taking advantage or notice of the acoustics present; and ultimately ending in deliberate attempts to manipulate acoustics in order to support speech and music in venues such as Paphos Theatre. The apps described in this study aim to allow users to phenomenologically examine that development of acoustic ecology in the three case studies described and evaluate these developments themselves.

4 Caves

During field studies of the acoustics of the caves, multimedia artist and archaeologist Dr Aaron Watson created a series of photogrammetric studies. A large number of digital photographs of each selected site in the caves were stitched together with software to create computer models of them. These were later imported into Unreal Engine. The imported visual models were virtually lit with a flickering candle-like effect; the resultant lighting is dim, only a small patch of light is visible, to reflect the simple lamp flames that would have been available in prehistory, perhaps burning animal fat (De La Rasilla et al., 2010). Interactive movement was implemented along a fixed track. The photogrammetric models were all of particular sections of wall that featured cave paintings, and covered only a limited area. The amount of motion possible for the viewer was restricted, so that it was not possible to wander off into the darkness. One can move towards the rock art to see it more clearly, and in a VR version of the app for the Oculus Rift headset one can look around with torso, head, and eye movement.

The app has a number of positions that can be selected. For example, a large wall section in El Castillo cave is depicted (Figure 1). This image features a number of red dots, one of which has been dated as more than 40,000 years old, one of the oldest known examples (Pike et al., 2012). The panel also features a number of red hand stencils, as well as yellow bison. Another model is of La Garma cave (Figure 2). This site is only accessible to archaeologists working on the site and only a few hundred people have seen the rock art since prehistory. These apps offer a wider audience the chance to experience them virtually, without damage to the archaeology. The imagery shown includes three hand stencils. These prehistoric images are so well defined that on one of the hands can be seen a thumbnail, and on another, a bracelet can be seen on a wrist. The hands are small, researchers have suggested they belonged to children or women (Fernández-Navarro, Camarós, & Garate, 2022; Snow, 2006). These motifs are at the farthest end of the cave from the original entrance, and are next to a deep drop to an underground river.

Figure 1

El Castillo cave panel as depicted in the VR app.

Figure 2

La Garma cave hand stencils as depicted in the VR app.

A model of Las Chimeneas cave features black Magdalenian images of a deer, bull, antelope, and stag in a small hidden side chamber (Figure 3). Two models of La Pasiega cave are presented: one is of a narrow channel at the end of a long corridor featuring a red horse painting, the second is a small hemispherical chimney with horse and deer paintings. Neither of these two caves are open to the public, and this software offers audiences unique access to these Palaeolithic sites. All these four caves are in Cantabria, three of them are in Monte Castillo hill in Puente Viesgo, while La Garma is in a separate location. Tito Bustillo in Asturias was the final cave modelled, which is a large show cave that is open to the public (Figure 4). The model of Tito Bustillo depicts a large panel featuring numerous images of horses. This is an unusual panel, as it features polychromatic images, using, for example, purple fill of a black outline. The images presented range from c. 12,000 to 40,000 years old (Fazenda et al., 2017).

Figure 3

Painting of a stag from Las Chimeneas cave, image taken from the Soundgate OSX app.

Figure 4

Tito Bustillo cave as depicted in the VR app.

An app was developed, initially for smartphone, tablet, PC, and Mac which includes sound features alongside the visual models of the caves. Within the app, one can explore the sites virtually, and in addition, a number of sounds that were recorded anechoically (without reverberation), may be played by the user to stimulate the acoustic responses of the spaces. These include a replica of a Mansi drum made from spruce wood and reindeer skin by Juhana Nyrhinen in Finland; the original is in a museum in Finland, collected by Finn Artturi Kannisto on an expedition in 1906 to West Siberia. This is the style of drum used by Siberian Shamans (Rozwadowski, 2015). The drum in the app can be played as a single beat or a repeating pattern. A few notes recorded on an archaeological replica of a 30,000-year old vulture bone pipe from the French Isturitz cave can also be played by the user. This instrument was reconstructed from a Griffon Vulture bone by Dr Simon Wyatt, who also played the instrument (García Benito, Alcolea, & Mazo, 2016). The Spanish caves were all sited close to the sea, and the final sounds that can be triggered are a range of sounds made with scallop shells of the type found in the caves; scallops were eaten in these caves in prehistoric times. A demonstration of this app, screen captured from an Apple Macbook Pro laptop, can be seen online.^[1]

These sounds are fed through convolution reverberation software by the app; this adds the impulse response of the relevant cave to the sound of the musical instruments, imparting its acoustic fingerprint. An impulse response was captured next to each example of cave art one can see in the app; thus, in each cave, one can hear the sound of the cave illustrated with a musical example featuring and demonstrating the acoustics present. Middleware fMod (n.d.) is used to implement the audio. This software transfers sound materials into the Unreal game engine used to author the app, which can output interactive apps in various formats. Before one enters the interactive element of the software, where one can explore the space and sound at will, a video file plays that has been rendered from Unreal Engine, accompanied by an audio recording made in situ in each cave.^[2] These recordings include bullroarers (Morley, 2005), the Isturitz vulture bone pipe/flute replica, the sound of rushing water coming from a large chasm nearby, the Siberian drum, a version of the Isturitz pipe being played with a reed inserted, a cow horn trumpet, instruments played (La Pasiega models) in a long corridor-like space, at some distance from the listener, and two shamans’ drums played together. In each case, we played a range of instruments in the caves, and selected materials that sounded most effective, or best illustrated the acoustics present, for the film previews of the interactive digital models. Thus, on launching the cave apps, initially one hears recordings made in situ with various instruments heard in the localised acoustics while watching a rendered video, and subsequently one can interactively explore the caves and trigger anechoic sounds with added convolved acoustics.

5 Stonehenge

About half of the stones of Stonehenge are today missing from the monument or have fallen, meaning that it is difficult to appreciate how the site might have appeared or sounded in the past. The Stonehenge apps used acoustic modelling software Odeon (n.d.) to digitally generate impulse responses representing the acoustics of the site in the past, using acoustic ray tracing technology. English Heritage (now Historic England) granted a licence to adapt their photographic scan from 1994 for visual digital modelling. Discussing future use of these data Bryan and Clowes (2000, p. 61) had suggested that “the basic 3D data, for instance, is suitable for further computer rendering.” The data were received as a set of individual point clouds of single faces of a stone, often requiring three separate files for each stone. I worked with designer Andrew Taylor and 3D expert Dr Urtu Unver from the University of Huddersfield to develop the data into a complete 3D model. The point clouds were stitched together into whole stones, and placed onto a virtual landscape surface developed from LIDAR data of the surrounding area (Figure 5). This LIDAR data were cleaned to remove modern features. The bank, ditch, and avenue approaching Stonehenge were enhanced in size and depth to replace the erosion of these features. The model was surfaced and textured (Figure 6) using photos taken at the site. Initial animations were video rendered, and the model was geared up with basic interactivity, allowing a character to freely explore the site (Unver, 2011; Unver & Taylor, 2012).^[3]

Figure 5

Stonehenge model mesh from point cloud and surfaced image.

Figure 6

Stonehenge model mesh from point cloud and surfaced image.

In Unreal Engine were added foliage, appropriate lighting (Figure 7), and versions featuring the various developmental arrangement phases of the site. In the earliest dated arrangement, only a bank was present; a later phase featured Welsh bluestones arranged within the bank in a large circle (Figure 7); subsequent models featured comparatively local large Sarsen stones added in the monument’s final arrangements. DXF versions of the model were imported into Odeon acoustic modelling software to generate impulse responses for various source/receiver positions and phases. Three different lighting and environmental states were created, one representing midday (Figure 7), another near sunset (Figure 9), and a third at night (Figure 8, Figure 10). Animated clouds and black birds flying high overhead were added to the daytime model (Figure 7), with a low evening sun providing long shadows and a red glow Figure 9). The team visited the site, and were inspired to include images and sounds of the rooks, jackdaws, and crows that live at Stonehenge, and even nest amongst the sarsen stones. Trees were added according to archaeological information about local gradual deforestation, along with other vegetation. Animation was set at an appropriate eye-height based on approximation of average human heights at the time.

Figure 7

Image from Interactive Soundgate App for OSX.

Figure 8

Image from Interactive Soundgate App for iPad.

Figure 9

Image of Soundgate from VR model.

Figure 10

Image of Stonehenge from VR model.

Using FMod, environmental sounds were added, including subtle wind noise and bird song. In the daytime versions of the model, jackdaw, rook, and crow calls are mixed with sounds of British songbirds and pigeons. A random function places these sounds in different positions around the monument, at different times, and at different volumes. In the night-time version of the model, the moon and stars replace sun and clouds, while owls, corncrakes, and nightingales replace the daytime birds. Nightingales and corncrakes are now rare in UK, but both would have been common sounds at night at the time of Stonehenge’s construction.

Anechoic drum sounds can again be triggered by the user. Also playable are notes from a model of a crane bone musical pipe found in Wilsford (Wiltshire Museum, n.d.), which is around 13 miles from Stonehenge (Hunter & Woodward, 2014, pp. 114–117), from roughly the same period. Dr Simon Wyatt was recorded playing his replica of this archaeological find. The soundscape created is processed through a convolution reverberation effect in the app, digitally adding the reverberant field generated by the stones.

Three separate impulse responses are used within each date phase, each generated using Odeon modelling. The app mixes these reverberant fields, so that the acoustics heard change as the user moves around the site. This allows a reasonable simulation of the reverberation change as one approaches the stone circle, enters it, and then walks into the centre. The most apparent effect present is a short echo. None of the illustrative sounds in the apps have enough low-frequency energy to be changed dramatically by the low frequency resonances present, although some effect can be heard on the drum. Bird and environmental sounds are also processed. The effect is a small but noticeable reflective reverberation, as well as a short echo. I validated and evaluated these effects on site, both at Stonehenge in its current state, and at a concrete model of the site in Washington State in the United States, called the Maryhill Monument (Fazenda, 2013).

6 Paphos Theatre

An all-white archaeological reconstruction of the Paphos Theatre was provided by the Cyprus Institute (Omnia, n.d.; Paphos Theatre Archaeological Project, n.d.), and is based on excavations carried out by them with the University of Sydney. The model was coloured, textured, and interactivity implemented using Unreal Engine. Again fMod was used to create a relevant soundscape, with playable studio-recorded musical examples. This has added reverberation that was digitally modelled using Odeon software, and which changes as one moves around the space. Whereas in Stonehenge, the acoustics present are quite varied, here the reverberant field was diffuse, and hence the acoustics were similar across the space. The Cave and Stonehenge sections of the app had been set as if the listener is carrying any musical instruments. In the Paphos model, the recordings of musical performances are digitally placed at the front of the venue, because Paphos has a stage and is a performance venue with a specific orientation. One hears less of the direct sound from the instrument, and more contribution from the theatre’s acoustics as one moves away. The theatre is near the sea, and the distant sound of waves is added to a background soundscape, along with the sound of large pieces of material shading the audience flapping in the breeze, two local birds (the Cyprus Wheatear and the Cyprus Warbler), seagulls, doves, and pigeons (the latter two were kept domestically by the Romans).

Examples of two Roman musical instruments can be triggered by the user. One is the Tibia, a double-reed instrument, similar to a modern oboe. Tibia, known to the Greeks as the Aulos, are played in pairs using circular breathing, one in each hand, equivalent to playing two oboes at once with no gap to breathe. I recorded these instruments being played by Hagel (2016). I recorded a second performance, this time by John Kenny, playing an Etruscan Lituus, an instrument that is very similar to the Roman equivalent (European Music Archaeology Project, 2016). As in the other sites, a rendered video that explores the space plays on entering the digital model in the app version, and this video features recordings of both instruments, featuring modelled acoustics.

7 The Soundgate

An interactive app was developed in Unreal Engine that allows the user to choose one of the sites and its models (Till, 2021). An installation of this app was created for the EMAP exhibition Archaeomusica (European Music Archaeology Project, 2018), called the Interactive Soundgate, featuring a gamepad, 42 inch display screen, and headphones (Figure 11). A large projected version was also displayed on a 12 m × 2 m semi-circular screen, alongside live footage shot in Scotland and in Sweden; this was a fixed, rendered film (Figures 12 and 13). The exhibition toured to venues in Sweden, Spain, Slovenia, Cyprus, Italy, and Germany.

Figure 11

EMAP Exhibition Interactive Soundgate version of app.

Figure 12

Plan of Soundgate museum exhibit large projected version.

Figure 13

Soundgate museum exhibit large projected version.

As well as fixed installations of the Soundgate, an app version was created for iOS (iPhone, iPad) and Android devices, with assistance from University of Huddersfield staff, and Huddersfield software company Torchbearer Interactive (n.d.). The Windows and OSX versions provide high quality graphics but are demanding of system resources, and without a powerful computer, frame rate can lag due to the size of the model(s). Smartphones and tablets could not handle such a large model, and thus the graphics were somewhat simplified and optimised for these platforms. This compromise was worthwhile in order to disseminate the research to a wide public audience on these popular formats. PC and Mac versions were also made available online. The app version of the Soundgate [3.5] was released on the EMAP website in 2017, and there have been 4,678 downloads to date from UK, USA, Japan, China, Australia, Brazil, and throughout Europe. A version was also shown as part of the “Klang der Antike” exhibition at Würzburg’s Martin von Wagner Museum in 2019/2020, and in widescreen format with 5.1 soundtrack at Bradford’s National Science and Media Museum’s Widescreen Weekend event in 2019.

8 VR

A VR version of the app was created for Oculus Rift S headset. This has a number of advantages over other forms of interactive display of results of music archaeology and archaeoacoustic research. “The use of multisensory stimuli, embodiment, storytelling, responsive characters, emotivity, or enhanced interaction has taken Virtual Reality (VR) applications in Archaeology beyond the traditional visualization of 3D architectural models” (Pujol-Tost, 2019, p. 1). Within a VR context, audio and vision are a more fused perception than in for example an interactive tablet app. On a conventional flat screen, there is a surround to the screen, and you can see your everyday surroundings beyond. This limits the sense of immersion or flow (Csikszentmihalyi, 1992) that can be created, as there are distractions present that reduce the level to which one can be lost within the experience, the level of suspension of disbelief that is possible. Music and audio on a tablet might be presented through loudspeakers, and also offer acoustic and other sonic distraction. Headphones provide a greater sense of immersion, blocking out the acoustics of the surrounding space and its acoustic ecology. The VR headset does the same thing for vision, blocking out everything visually other than the digital interactive model. VR headsets, therefore, offer both audio and vision a level of immersive experience beyond other platforms. Further, audiences are used to VR and computer modelled environments to be audio rich in commercial games. Indeed, research has found in the study of the success of VR in archaeology that a “lack of sound disrupted the participants’ experience in 38.3% of cases” (Pujol-Tost, 2019, p. 10).

Audio resources are important in helping to deepen immersion, to move from engagement and engrossment to total immersion (Brown & Cairns, 2004), which indicates an experiential extremity. In terms of flow, which is interchangeable with immersion, this means to move from micro-flow towards deep-flow (Pujol-Tost, 2019). In order to create an experience that is as powerful as possible, one has choices. In our case, we have chosen to avoid interaction with avatars or animated human characters of any kind, as we find these to be clearly digital, and to have the potential to detract from the mechanisms required for a sense of total immersion, “concentration, loss of self-reflection, distortion of time perception and autotelicity, all of which make flow inherently dissociative from reality” (Michailidis, Balaguer-Ballester, & He, 2018, p. 1682).

In our apps, acoustics, sound, and music are the key focus rather than gameplay or interaction with characters or activities. The VR experience aims for a sense of presence, a sense that one is actually present in the virtual space perceived. Although this can only be partial, rather than some kind of virtual time travel, a sense of presence is one of the aims of our model, in addition to immersion/flow, the latter comprising an altered state of consciousness, whereas the former does not. Immersion is defined as:

a phenomenon experienced by an individual when they are in a state of deep mental involvement in which their cognitive processes (with or without sensory stimulation) cause a shift in their attentional state such that one may experience disassociation from the awareness of the physical world. (Agrewal, Simon, Bech, Bærentsen, & Forchammer, 2020, p. 407)

Immersion is related to a sense of presence. This definition is from an audio research context, but takes into account research in other fields. Sound assists immersion, which contributes to a sense of presence, but presence needs visual or musical contextual cues. Audio rich VR is used in this case within a VR headset experience in order to increase immersion, flow, and presence in comparison with that achieved through earlier apps for tablet, PC, and smartphone.

A different VR model of the Paphos Theatre was created by another research team (Barker, 2018), and released later in the same year that our own model was released. It is interesting to compare this app with our own. This other model implemented VR on a 3D headset, but only at three specific positions. Our model was created for a museum exhibit, and thus provides a moving guided tour of the venue while the viewer looks around. This other app has a focus on visual archaeological detail, “It was important to capture the look and feel of both imported marble and local Paphian limestone surfaces, the blue marble slabs for the orchestra floor, painted surfaces for the parodoi entranceways” (Barker, 2018, p. 10); this is described in detail. In our app, phenomenological detail was the focus, thus sound was a key focus. Although in the other app “a soundscape was added and a voiced narration” [ibid], no detail is added of how the audio was constructed. A flythrough provided by the app developers (Lithodomos, n.d.) features a modern operatic musical soundtrack, and birdsong seems to provide the soundscape. The voiceover provides valuable contextual information on the app, but disrupts a sense of immersion, although the creators state on their website that it is intended “to enhance the experience of immersion, that the viewer once they wore the 3D google set was actually in the theatre in a late afternoon in, say, 161 AD” (ibid). The Australian accented speech present makes it clear that this is a modern experience. Our own research, with a clear focus on sound, and this other app, coming from an archaeologist’s perspective, have different purposes and priorities, and inevitably produce different results.

When using our VR app for Oculus Rift S headset, there is a powerful sense of presence. Having visited the caves and thus physically been present in the caves that are modelled, I find being in the app versions experientially remarkably similar to the original site. The experience was powerful, with a very strong sense of presence. A deep sense of immersion was also present. A number of elements of the app contribute to this experience, including lighting, realistic textures, accurate acoustics, and musical and visual archaeological content, and also that one’s visual and audio perception is completely dominated by the app.

Another significant impact is afforded in a VR headset from independence of torso, head, and eye movement, an issue that has been little discussed in studies of immersion, flow, and presence. “In our interaction with the world, gaze shifts are achieved through a combination of eye, head and body movements. We move the eyes in the head, the head relative to the torso, and the torso relative to the world” (Sidenmark & Gellersen, 2020, p. 1). On a PC, tablet, or smartphone screen, a flat representation allows one or two axes of motion, which is not natural or “realistic.” An eye can move across the screen and look at different parts of the model, but you are aware of the edge of the screen, and you have to use your hand to control the model if you want to move your field of vision, to adjust the frame you have to select the option in the model. In a VR headset you can twist your torso one way, while moving your head from left to right, and then pause and use your eyes to scan detail of the image, or manipulate all three axes independently and simultaneously. This results in a significantly more realistic and immersive experience, and a stronger sense of flow and presence, radically transforming the effectiveness of the same graphics presented by Unreal Engine through the use of a different technological platform. For music archaeology or archaeoacoustic research, this is particularly effective as for example in the app when one turns one’s head and looks to one side, a musical source playing a sound remains in its correct orientation. This could be further enhanced by using 3D audio, projecting a surround audio acoustic ecology using technology such as ambisonics or dolby atmos, to increase audio immersion (Popp & Murphy, 2022). 3D audio is a feature of many VR headsets and this is likely to become an increasingly important part of VR modelling.

9 Discussion

A discussion follows exploring: comparison of the modelling of the three sites, the effect of VR rather than other digital formats, assessment of the VR models of the three sites, discussion of what can be learned from the use of the apps, and the risks of inaccuracy.

The apps allow us to compare three different archaeological sites, three different eras and contexts, and three different approaches to modelling. The caves largely retain their material integrity today, thus photogrammetry could be used, which provides a highly realistic replication of the sites by combining numerous individual digital photos using software into a 3D photographic model. Because only about half of Stonehenge still stands, to fill in the missing sections, duplicates of existing stones were used. This rules out photogrammetry, the Stonehenge model was instead based on point clouds from scans of the site, with added photographic textures. At Paphos, a complete virtual rebuilding was needed, which was carried out using archaeological plans from excavations. Photogrammetry was most convincing in terms of replication, creating a highly realistic sense of immersion and presence. However, this modelling approach makes it difficult to remove modern features or change material degradation, as the author has found in work on other sites. Intact sites do allow for real acoustic impulse responses to be captured, which is useful.

The use of a mixture of photographic textures on the Stonehenge model from the modern site with scanned models of remaining features was effective as it allowed a range of lighting, weather and other effects to be applied. This approach inevitably introduces greater elements of uncertainty. It also affords the opportunity to illustrate multiple arrangements and possibilities. Having some of the existing site present allows one to capture impulse responses onsite which may retain part of the original acoustic of the site and help validate acoustic modelling results.

Building accurate models from scratch as in the Paphos model is time consuming, but as in this case, often models exist already from other archaeological studies. Creating a model from scratch encourages research into specific details, and allows for assessment of various interpretation options. In this case all Paphos acoustics are modelled, meaning for example that there could be difficulties replicating low frequency responses, in a low frequency range where ray tracing methods can be inaccurate. Overall, the apps illustrate the usefulness of a multi-sensory archaeological approach within digital models, to allow for the replication of elements such as lighting, weather, textures, and foliage as well as soundscape, music, and acoustics, all of which were found to be highly significant in affording an experience that can to some extent reconstruct for users what it might have felt like to be at the site in antiquity.

A key purpose of this research is to examine what we can learn about historic ritual sites from sonically rich interactive and VR apps. The acoustic effects in the apps enhance a sense of immersion and presence in the soundworld surrounding the user, just as acoustics contribute to an experience of otherness in the caves, both today and in prehistory. Combined with the impacts of sensory deprivation, expectation, tradition, as well as cave paintings and engravings, the caves provided a particular and unusual audio-visual experience (Goldhahn, 2002). If place is space with context, acoustics have a significant role in creating a sense of place for the user. The experience of using these apps showed that cave paintings and engravings can contribute to the understanding of their context through multi-sensory archaeology, and can help the user to appreciate the significance of sound in that context.

VR in particular shuts out the external surrounding audio-visual field, and allows one a sense of the presence one might have felt in the caves. Compared to the use of the cave apps on smartphone, PC, or tablet, with a VR headset on users found that the fact that one could not see the modern surroundings of the room makes a significant contribution to feelings of flow, immersion, and presence. When tested without sound, the VR experience felt very unnatural, with audio included, one felt a greater sense of place. Further study is needed to quantify the level of these effects beyond the experience of the research team and other individuals who have tried the VR app thus far. Having been in the actual caves, comparing the VR recreation the author can confirm that the VR apps provide a viscerally convincing phenomenological experience of these spaces; they do provide a strong sense of presence that reflects the reality of the original sites. This also causes one to recall the impact of the original visits to the sites. It underlines the remarkable power and impact of the imagery and sound present. Since many of the caves have restricted public access to protect them, these models have great potential for researchers and the public to understand these historic cultural landmarks.

Paintings and engravings on stone walls turn spaces into places of particular significance, raising their status above those things associated with everyday life; the acoustics associated with them assist entry into immersive deep flow states, enhancing the power of these images, and the cultural significance of these places. The apps are certainly more powerful with a relevant soundtrack than without. The suggestions of Lewis-Williams (2004) that caves are places of shamans, or shamanistic practices may be overly specific, but experience within the VR reconstruction helps users to asses to what extent painted caves may have been particularly sacred places with associations with animism and altered states of consciousness; they assist in the assessment of interpretative hypotheses. The cave apps provide disconnection from the outside world’s markers of the passing of time.

The acoustic ecology in the cave apps is very quiet, static, silent, and visually different from much of the landscape beyond, with stark stone structures, no sky, sun, cloud, or wind, little living plant life, few animals, few living beings, dark but with no stars or moon. Like the caves themselves, the apps offer an intersubjective experience of whatever is represented by the cave art present. The VR app, in particular, has many echoes of this subterranean world, as an eternally dark place, featuring images and sounds that connect us to our ancestors. Affording something other than everyday reality, perceptions of time are distorted affording total immersion in a presence of the past, and we are offered a ritualistic opportunity to explore issues related to our relationship with the context present.

Stonehenge was built across an era during which humanity began to become agriculturally focused, people choosing spaces for settlement, and beginning to create large stone monuments that afforded acoustic effects. Architecture, ancestors, acoustics, spirits, seasons, sun, calendar, and dates were all mixed together in group ritual activities, in which sonic effects were present, as they were in caves. Humans began to exert control over their environment and their lives. These sacred places are a reflection of their changing relationship with their cosmology, with time, with places, with the past, with their future, and with existence. The different phases of Stonehenge’s arrangement changed the way that the space responded sonically, and the apps afford the user the opportunity to experientially explore similarities and differences between these various phases. It also allows users to compare these acoustics with those in the caves. Whereas the acoustics in the caves were present before they were marked as sacred by paintings and engravings, the visual and acoustic cultures of Stonehenge are human-made, sitting in the landscape.

It can be difficult to imagine how these archaeological remains would have looked when intact, and it is more difficult still to understand what an experience of a site might have felt like. Bailey (2017) explored the use of art in archaeological interpretation, and suggested extending beyond the boundaries of either art or archaeology, into digital approaches such as used by these apps. In the Stonehenge apps, the role of the large bank and ditch as a first monument is illustrated. The bank absorbs sound from outside, creating a sense of sonic enclosure, as well as blocking sightlines to the centre. Our perception is a fused process of looking and listening (Ingold, 2000), and the bank and ditch alone change our perception of this space. Inside the later, stone circle is a space set aside, perhaps for the ancestors (Parker Pearson et al., 2020), separated from the natural landscape as a home for the spirits of the dead (Willis et al., 2016). The app is effective in illustrating the differences between the changing arrangements of stones. The models of different phases illustrate well how their sense of acoustic and visual enclosure varies as the user moves from the edge to the middle of the circle (Till, 2009, 2011, 2019).

When using the app the author found it striking how hidden the centre of the circle is from the outside in the final arrangement of stones, especially compared to the first arrangement of bluestones in a wider circle inside the bank. This suggests a level of increasing cultural stratification, sections of space ascribed greater power compared to others, the external excluded, something that is reinforced by the acoustic isolation afforded by the grass bank and Sarsen stone ring. The app also illustrates how separated one is from the exterior landscape by the stones, that one feels inside something separate, and that the lintels and uprights act to create a sense of a doorway. The way that the circle of huge Sarsen lintels forms a circle that frames a section of sky and stars and separates it from the ground, is especially well illustrated by the night time version of the Stonehenge VR app, something that cannot be experienced at Stonehenge today as so many of the lintels are missing. It is suggested that these are the kind of observations that archaeological specialists might find useful to explore, and that are powerfully experienced through direct engagement with images of the site, rather than intellectual conceptualisation.

In the twenty-first century, as many as 20,000 people gather at the site on the summer solstice. The “avenue” that leads to Stonehenge is aligned to the rising and setting of the sun on the summer and winter solstices (Allen et al., 2016), as is the entrance to the monument itself. The apps allow users to explore this alignment by virtually watching the sun rise from the site’s centre on the morning of the summer solstice, without being affected by clouds or crowds. They also allow the user to explore how sound contributes to the experience, to observe the echoes focused at the centre (Till, 2009) enhancing its acoustic ecology.

Stonehenge shows echoes of the acoustics of caves. The interactive models of these sites offer an opportunity to phenomenologically gain a visceral experience of them, to understand how human ritual sites have changed over time, and how their acoustics have changed and developed. In the caves and at Stonehenge, one moves from the outside landscape into the inside of the monument, from an external natural space, to a place adapted by humans to explore their beliefs and histories. At Paphos theatre one leaves nature to enter a place created from carved stone by and for humans that excludes any view of the surrounding natural environment. Paphos theatre is a building whose visual and acoustic ecology is consciously designed by humans in order to create a place where ritualised entertainment is afforded, featuring acoustics that are enhanced by intentional intervention. At Paphos Theatre, humanity exercises powerful control over its environment. Its controlled acoustic ecology contributes to highly organised ritualised celebrations.

The Paphos app illustrates social stratigraphy well, for example the model allows one to explore how seats at the back or sides provide a less ideal view. The acoustics present illustrate how the perception of reverberation level increases as one moves away from the front, the comparative levels of source and reverberation enhance a sense of distance as one moves towards the back row. It soon becomes clear that there are a range of seating choices, from close-up direct connection to performers, through a helpfully raised position featuring flattering reverberation, to feeling distanced a long way back with reverberation loud compared to the source signal and natural sounds such as bird calls becoming more audible.

The apps illustrate our human journey through time and space: beginning with the natural stillness of cave sites; moving on to explore stone circles as human places formed by encircling areas of space in the landscape; ending with a statement of cultural power at Paphos Theatre through creation of a wholly artificial place. We see in the VR apps themselves today’s equivalent of these three case study sites. The apps are places created by humans by offering audiences explorations that separate them from the everyday world. The apps and sites all use audio and visual elements to enhance participants’ immersion and presence in whatever event is taking place.

One difficulty with trying to use phenomenology to explore intersubjectivity in terms of an understanding that bridges ourselves and the people of prehistory is the vast temporal gap that yawns between the two. An important task for archaeologists is to attempt to understand both the past and the people of the past, and in all cases the gap between the past and present is an issue. Where there are written texts, we are aware that victors and elite classes write selective biased histories, and all evidence requires interpretation to understand it; postholes do not tell us all we wish to know about rooves; the exact use of a found object is increasingly unclear as temporal distance increases, and the meaning of that object is even more difficult to define certainly. In many ways, such research tells us more about ourselves than it tells us about antiquity and its residents.

We cannot be certain that these app-mediated experiences of past places are similar to our ancestors’ experiences, but they afford us the opportunity to reach back towards those who came before us. It is important to acknowledge that attempts at understandings of experiences of the past cannot be certainties, but the apps help us to contextualise numerical metrical results, to better understand these sites of significant ritual and cultural richness and complexity. Interpretations are offered with the express understanding that they may be more useful in telling us about human cultures today than informing those of the past. At the very least, self-understanding is a worthwhile activity. As a methodology rooted in the arts, VR archaeology accepts its limitations and acknowledges its shortcomings, but continues in preference to making no attempt for fear of failure or inaccuracy.

10 Conclusion

Although reconstructions always involve some level of interpretation and uncertainty, these apps allow users to explore possible similarities and differences between a number of archaeological sites as they existed in the past, especially in terms of the acoustics present, their relations to their visual and material environment, and the nature of our visual and aural perceptual experiences. The apps afford exploration of how perception (looking and listening) is mediated and interpreted. Sound has the advantage of intensifying immersion, connecting us to spaces acoustically, and to places contextually. Our thinking is most likely very different to that of prehistoric communities, but this digital embodied experiential approach offers one particular understanding, with a sense of presence, flow, and immersion as its strength and uncertainty as a weakness. The apps encourage users to reflect upon and evaluate their own experiences, rather than presenting one specific interpretation. Especially where written texts explaining an archaeological site are limited or unavailable, this approach provides a methodology for studying through engaging directly and bodily.

This approach offers an audio-visual, interactive, immersive experience, a phenomenological way to examine the sites chosen. At present, the interface of the apps described offers little built-in text, little information on the sites being explored, encouraging the user to focus on their experience and draw their own conclusions about meaning and interpretation. The sounds of the space are experienced as an integrated approach to looking at and listening to the spaces. One conclusion that the apps offer is an impactful appreciation of the variety of ritual acoustic ecologies present in the past, without requiring any specialist knowledge or understanding of acoustics. Acousticians, musicians, and archaeologists can explore sound as they may have existed at these archaeological sites, and evaluate what the acoustic ecologies experienced suggest in terms of a range of possible theories or interpretations. Future work could explore a larger range of archaeological sites, extend interactivity by acoustically processing microphone input, afford interaction with activities in the apps implementing elements of gameplay, introduce textual information about the archaeological context, introduce virtual characters and avatars to represent human agents present, include 3D video of the current sites, allow networked users to interact with each other within the app, place the apps in virtual meeting spaces, introduce 3D audio such as ambisonics or Dolby Atmos, and evaluate the responses and experiences of users.

An important conclusion from this research is that music, acoustics, and sound can play a valuable role in virtual archaeology and archaeological modelling, through use of interactive models, especially VR. It suggests that researchers should apply similar rigour to the sonic qualities of any digital model as they do to its visual context, and work with those with expertise in sound to achieve results using best practice. This research project suggests that VR is particularly effective in achieving high levels of immersion and flow, as well as a strong sense of presence, especially if attention is paid to sonic content. VR and other audio-rich immersive multimedia are shown to be an excellent way to present the results of music archaeology, archaeoacoustics, and sound archaeology research. The apps offer a novel way for scholars to explore archaeological sites through multisensory, virtual, and digital archaeologies, and explore new perspectives on their understandings. They offer a form of phenomenological embodied experiential approach that provides a complimentary pathway to quantitative metrical approaches, and has strong potential for impact, dissemination, and engagement for a range of academic and public audiences. This research is effective as a non-representional theory (NRT) compliment to purely empirical studies, allowing understanding that goes beyond binary dialectics, and addresses the real-world complexities of acoustic ecologies.

This research concludes that the apps presented here provide a contemporary contribution to the long history of human attempts to understand our relationships to those who came before us. The creation of archaeological apps echoes the work of Palaeolithic painters in caves, of the creators of megalithic architecture, and of the builders of carefully designed open air performance venues such as in Paphos. Digitally created environments existing beyond nature, archaeological audio-visual apps can help us reach back towards our roots to help us understand who we are and where we came from.