Individual differences in intra-speaker variation: t-glottalling in England and Scotland

3.1 Data collection

Data for this study were collected in a high school in West London and one in Edinburgh in 2009. Students were interviewed in friendship pairs of matched origin. The sample consisted of 24 London-born teenagers (12 males, 12 females) and 21 Edinburgh-born teenagers (8 males, 13 females). Community-focused results have already been reported in a cross-varietal study in Schleef (2013) and more detail on data collection is available there. The teenagers were all aged between 12 and 18, with a mean age of 14. Two locally-born female research assistants carried out sociolinguistic interviews, which were transcribed orthographically.

Speakers were also recorded performing a short reading task of 17 sentences that had been designed to elicit a wide range of different phonological variables. The reading task always preceded the interview (for a discussion of order see Meyerhoff et al. 2015: 51). Combining reading and conversational data provides a measure for comparing differences in speech style, in the Labovian sense of attention paid to speech (Labov 1972). The shortcomings associated with using reading and conversational data to elicit different styles are well known, see for example Schilling-Estes (2002: 382–383). Most notably, this method is unidimensional and cannot capture the multitude of different speech styles one may encounter in naturally-occurring speech. Nonetheless, this method can give us some indication of more formal versus less formal speech, and it also allows us to compare the current data to those of other studies.

3.2 The dependent variable: /t/

This study focuses on the variable realisation of /t/, in particular, the alternation between [t], which includes variants, such as [t^(h), ˀt, ˀt^¬ , t^¬ , t̬], and glottal replacement of /t/. These two main variants have been coded auditorily. Each realisation of /t/ occurring in the relevant envelope of variation (i.e. /t/ after a preceding sonorant in coda or non-foot-initial onset position) was coded independently by two research assistants. Cases of coding disagreement were discussed with a third researcher and mutually agreed, sometimes after visual inspection of the acoustic properties of particular tokens. The coded data were then imported into Excel for further coding, e.g. for word frequency, grammatical category, style, etc. Not all function words were included in the analysis. Only the first 10 occurrences each of the high frequency function words it, at, but, out, that, not were coded per speaker. This generated 2524 tokens of /t/ from the London-born speakers and 2633 tokens of /t/ from the Edinburgh-born speakers.

3.3 Coding for linguistic and social constraints

T-glottalling is spreading rapidly in Britain and is now perceived as stereotypical of British urban speech in general (Britain 2005: §3; Milroy et al. 1994: 328). The literature on t-glottalling is quite extensive, and it is reviewed here very selectively in order to identify factors that previous research has found to constrain variation of /t/.^[1]

Previous studies typically examine (1) the position of /t/ within the word (normally finding that glottal replacement occurs more frequently word-finally than word-medially – cf. Roberts 2006, but see Smith and Holmes-Elliott 2018); and (2) the phonotactic environment (often finding that following segments or prosodic boundaries influence the variability of /t/ in statistically consistent ways – see Drummond 2011; Fabricius 2000; Milroy et al. 1994; Straw and Patrick 2007).

The preconsonantal environment usually favours glottal variants the most; the prevocalic environment tends to disfavour it (Straw and Patrick 2007: 390). Findings tend to be constant, but some regional particularities have also been identified (cf. Docherty and Foulkes 1999; Roberts 2006; Smith and Holmes-Elliott 2018). Schleef (2013) found word frequency to be a relevant linguistic factor: more frequent words favour glottal replacement among adolescents in Edinburgh and London. Several social constraints have been investigated in previous research and are often found to be significant for t-glottalling:

1. Style: t-glottalling is normally less frequent in formal style (e.g. Holmes 1997, but see Smith and Holmes-Elliott 2018).

2. Age: t-glottalling is more frequent among young speakers (e.g. Fabricius 2000; Roberts 2006; Williams and Kerswill 1999).

3. Socioeconomic class and gender: generally, there is more glottalling as one goes down the social scale; however, social class often interacts with gender and the pre-established patterns of use of t-glottalling in an area to generate unique, new patterns (e.g. Holmes 1997; Mees and Collins 1999; Milroy et al. 1994; Roberts 2006).

In the current study, mixed-effect multiple regressions were conducted in R (R Core Team 2019) with style (speaking, reading), social class (working class, mixed, middle class), speaker sex (male, female) and several linguistic factors as fixed and speaker as random effect. This procedure considers individual variation when generating the statistical model and, thus, strengthens our confidence in the model. It allows us to study group patterns while also investigating variation at the individual level.

4.1 Community patterns

Position, i.e. where in a word /t/ occurs, constrains glottal variation of /t/ in a highly consistent way. Glottal replacement is much more likely in word-final position. Schleef (2013) created separate models for these two positions in both London and Edinburgh, and he found style to matter in all of them: t-glottalling is significantly more frequent in conversational than in reading style with p-values below 0.001.^[2] This effect is more pronounced in word-medial position due to the more pronounced stigma attached to word-medial glottal replacement, especially intervocalically (cf. Fabricius 2000: 141). As the exclusive focus in this paper is on style, I will not go into further detail here (see Schleef 2013 for further information). In brief, the following factors favour t-glottalling: preceding vowels and following nasals, liquids, fricatives and affricates. More frequent words are more likely to be glottalled, but the frequency effect is much stronger in word-medial than in final position. In fact, there is no significant frequency effect in word-final position in Edinburgh. Finally, in both cities, there is a strong effect of grammatical category in medial position, for example: function words and verbal progressive forms favour t-glottalling.

4.2 Individual differences: Degree of style-shifting

What matters for the following argumentation is that at community level, there is clearly a significant style effect. Next, I created separate regression models only including style as a fixed factor in order to conduct a direct comparison between London and Edinburgh on only this one factor. An inspection of the random intercepts suggests that in the medial contexts, the style-shifting behaviour is similar in London and Edinburgh. Figures 1 and 2 show each speaker’s random effect, which gives an indication of how much that individual’s trend diverges from the predicted trend of the model. The closer the value is to 0, the less a speaker diverges from the pattern captured by the community model. Speakers with a positive intercept are more likely to glottal; speakers with a negative intercept are less likely to glottal than the model predicts.

Figure 1:

London random intercepts (medial).

Figure 2:

Edinburgh random intercepts (medial).

Figures 1 and 2 are indicative of a substantial degree of interspeaker variation in both places. While the two figures do not look too dissimilar, the standard deviation and variance are higher in London than they are in Edinburgh (see Table 2). Figures 3 and 4 gives an indication of individual differences in word-final t-glottalling. Table 2 indicates that the degree of interspeaker variation in respect to the model is reduced in final position, when compared to medial position in both London and Edinburgh. Whereas in medial position variance was larger in London than in Edinburgh, in final position the difference between the two places is minimal.

Figure 3:

London random intercepts (final).

Figure 4:

Edinburgh random intercepts (final).

Thus, by means of an intermediate conclusion, I can record that individual differences in the degree of style-shifting differ by place and linguistic context. Individual differences are most pronounced in medial position in London, followed by medial position in Edinburgh, final position in Edinburgh and final position in London.

4.3 Individual differences: Direction of style-shifting

While the two statistical models show that speakers style-shift and that there are individual differences in the degree of style-shifting in both cities, it remains unclear whether all speakers shift towards the same direction. Figures 5 and 6 explore this for medial /t/ in London and Edinburgh, and Figures 7 and 8 provide overviews for final /t/ (see supporting files for percentage values). A comparison of medial /t/ in London and Edinburgh indicates that the community norms in London are very variable in speaking style, while they are more focused to below 30% glottalling in reading style. In Edinburgh, the situation is reversed. The reading targets differ widely but the conversational target varies less across the community: it is more constrained in Edinburgh at above 80% glottalling, and, according to Stuart-Smith (2003) obligatory for working class speakers, and optional but frequent for middle class speakers.

Figure 5:

Style among males (blue) and females (red) in medial position – London.

Figure 6:

Style among males (blue) and females (red) in medial position - Edinburgh.

Figure 7:

Style among males (blue) and females (red) in final position – London.

Figure 8:

Style among males (blue) and females (red) in final position – Edinburgh.

We can also observe that in both places the majority of individuals follow the style-shifting behaviour of the community, that is, they reduce glottalling rates in reading style. However, there are a small number of individuals who do not appear to show style-shifting behaviour. In London, Jill, a fourteen-year old working class female with an Indian mother and Jamaican father, does not style-shift at all. Jill has lived in London all her life.

In Edinburgh, five individuals do not reduce their glottalling rates in reading style. Four of these even use slightly higher glottalling rates in read speech. I regard these as cases of a lack of style-shifting rather than as context-induced increases in glottalling as the difference in reading and speaking is never more than 11%. The reading style data is based on a maximum of a 23 medial /t/-tokens, so even one glottalled token can have a large percentage effect. Of those five individuals, all are male, except for Skye, a fourteen-year old female. Four of the five are working class. Terrance, a sixteen-year old male, is middle class.

In regards to the question posed at the beginning of this paper, I can conclude that in medial position, the majority of speakers follow the community pattern, except for one individual in London and five in Edinburgh, which may be a reflection of the higher social salience and stigmatisation of medial t-glottalling in London when compared to Edinburgh.

In final position, individual style-shifting behaviour in London and Edinburgh looks more similar than it did for medial position. We still observe slightly more focused conversational glottalling rates in Edinburgh than in London but the reading targets are equally dispersed. Both London and Edinburgh also feature a number of individuals who follow the community model and reduce glottalling rates when reading, however, there is also a remarkably large number of speakers who do not style-shift at all. If we allow for a non-shifting 11%^[3] range in both directions, only four participants in London and six in Edinburgh shift to less glottalling in reading style. This is in stark contrast to what has been observed in medial position.

In Edinburgh, those who increase glottalling rates in reading style fall within a range of 11%, and I am inclined to regard these as non-shifters. In London, there are three individuals who have much higher glottalling rates in reading style than speaking style: Julie, John and Stein use respectively 12, 19 and 26% more glottalling in reading than speaking style. However, they stand out from the group not by their glottalling while reading but their high /t/-use when speaking.

This may be due to an important shortcoming of considering reading and speaking as homogeneous styles. While participants may not change their stance and style much while reading, the speaking parts of the interview allow various different personae of participants to surface that the current study cannot control for. Some of those personae constituted by John, Julie and Stein may be ones that are associated with more formal styles of speaking.

When considering the findings as a whole, it appears that the less socially salient context results in less style-shifting and fewer individual differences in degree of shifting, but more individual differences in the direction of style-shifting. The opposite holds true for the more socially salient context. Applied to the two cities and contexts, data from variance and social salience align with individual differences as detailed in Table 3.