Volume 39, Issue 4-5

In order to investigate the interaction between articulatory and vocal pitch controls, EMGs of the cricothyroid (CT) and sternohyoid (SH) muscles were recorded during utterances of two-mora Japanese words with rising and falling accent types in the Tokyo dialects. The test words consisted of combinations of open and closed vowels. It was revealed that the changes in CT activity were consistently observed in correspondence with the F₀ shift according to the accent types, while the SH muscle was observed to be active both for jaw opening and F₀ lowering, with some subject-to-subject difference. It was also observed that the time lag between the decrease in CT activity and the F₀ fall varied with a shift in the relative timing of SH activity in one subject, but not in the other. Articulatory jaw opening with SH activation was considered to positively contribute to F₀ lowering, but the use of this mechanism appeared to be optional at least in the Tokyo accent.

The contribution of fundamental frequency (F₀) to the distinction between lenis and fortis plosives is investigated for German in monotone, falling, and rising pitch patterns. A larger F₀ drop is found in the stressed vowel before lenis, as against fortis, in disyllabic words with the contour high + fall. These F₀ differences do not have aerodynamic causes due to articulatory constraints on phonation but can be related to an active laryngeal control in two production patterns differing in overall articulatory effort and also resulting in an articulatory timing contrast. Hypotheses are formulated as regards the importance of this F₀ difference for perception, and with respect to the production and the perception of the lenis/fortis opposition along the F₀ parameter in English.

In this paper the various pitch determination methods and algorithms (PDAs) are grouped into two major classes: time-domain PDAs and short-term analysis PDAs. The short-term analysis PDAs leave the signal domain by a short-term transformation. They supply a sequence of average pitch estimates from consecutive frames. The individual algorithm is characterized by the short-term transform it applies. The time-domain methods, on the other hand, track the signal period by period. Extraction and isolation of the fundamental harmonic, and investigation of the temporal signal structure are the two extremes between which most of these PDAs are found. After the review of these principles the paper finally discusses different application-oriented aspects, i.e., the role of the PDA in phonetics, education, phoniatrics, and speech communication systems.

In this article the problem of pitch period detection is discussed. The following statements concerning the nature of the problem are made: (1) Pitch period detection is a segmentation problem (in the technical sense of segment). (2) ‘Significant points’ are required as boundary points for the definition of segments. (3) There exists a visual recognition mode for segments in the speech signal. This implies the recognition of ‘significant points’. (4) The visually recognized segments may be related to auditorily recognized segments. Then an algorithm (‘skeletization’) is presented, which selects ‘significant’ points. The ‘significance’ of these points is examined. Characteristic properties of the suggested solution are didscussed.

Declination is taken as the focus of studying pitch phenomena from an acoustic, physiological and perceptual point of view. It is shown that originally declination was no more than a theoretical construct to account for the interpretation of acoustic F₀ recordings. Recently, psycholinguistic considerations have enhanced the domain of application so as to account for this phenomenon. The literature is reviewed and the authors take issue over the various claims put forward by others, such as the dominance of the topline over the baseline approach, and the amount of pre-programming involved in declination, as manifested in its slope and in linguistically determined resetting.

The present paper explores the textual function of intonation in indicating coherence and boundaries between successive utterances of speech. An informal listening test showed how such prosodic coupling can be used to mark coherence between sentences of a text unit. The coherence is expressed as a downdrift of F₀ peaks and valleys characterizing the whole text unit. The boundary between two text units is signalled by terminating one and beginning another downdrift ramp. The characteristic features of the downdrift pattern seem to be (1) an adjustment of F₀ values to the length of the text unit, and (2) an adaptation of the F₀ of the beginning of a succeeding sentence to that of the later part of a preceding one in the same unit. Some preliminary implications of these results for speech planning are discussed.

The paper summarizes project work on Swedish accents and intonation. One major goal was the development of a generative model for intonation. The input of the model is a text with markings for word and sentence prosody and dialect. The output is a realistic intonation contour. The model was first set up for statement intonation in isolated sentences from five prototype dialects. It was later applied to interrogative intonation, to transitional forms between the prototype dialects, to Greek and French intonation and to prosodic transfer in a foreign accent.

The basic property of pitch as a cue to linguistic stress is fundamental frequency (F₀) change . That leaves room for a lot of variation: in the direction of the change, the amount of change, and its exact coordination with the stressed syllable. Examples (from the literature) from a number of languages and dialects attest that they do indeed exhibit quite striking differences in the stress/F₀ relationship. The decisiveness, under certain circumstances, of the timing of F₀ events is illustrated by the results of a pilot experiment with a disyllabic Danish word: The location of a two-semitone rise from the first to the second syllable – before or after the intervocalic sonorant consonant – will shift listeners’ location of the stress.

The present paper reports on an experiment which was set up to examine whether we can make a speaker either accent or de-accent particular words by systematically varying the objective probability that a particular referent will be mentioned (and therewith the referent’s predictability for speaker and listener). In the experiment each of 24 speakers was asked to watch a visual display, showing a very simple configuration of letter symbols, and to describe orally each change in the current configuration to a listener. By manipulating the letter configurations shown on the display, the objective probability that the speaker would mention a particular letter could be controlled. Letters could either move around on the screen (moving letters) or remain fixed and serve as spatial reference points (fixed letters). Objective probabilities were 0.5 and 1 for both moving letters and fixed letters. The main findings were the following: (1) When a referent is fully predictable to speaker and listener there is a high proportion of ellipsis, particularly for the moving letter, which was always referred to from subject position. (2) The probability that a word referring to a letter will be accented appears not to be immediately controlled by the predictability of the referent. The controlling factor is rather the preceding linguistic context. More specifically, the probability of accenting, being close to 1 the first time a specific referent is mentioned, sharply decreases when the same referent is mentioned for the second time in a row, and decreases again when this same referent is mentioned three or more times in a row. However, as soon as the competing referent is mentioned once, in the same role (moving or fixed letter), the probability of accenting jumps up again. (3) The probability of accenting is systematically lower for the moving letters in subject position (average 0.32) than for the fixed letters in predicate position (average 0.52). In view of these findings, de-accenting, defined as conspicuously omitting an accent on a word that, for grammatical reasons, otherwise would have been accented, is interpreted as a device which can be used by a cooperative speaker for helping the listener to find the intended referent as easily and quickly as possible. It is supposed that speakers not using this device systematically give their listeners a harder time.