Labiodental variants

be possible. Given the impact of the presence of asublingual spaceon F3, Alwan et al. (1997) posited atrading relationbetween thesublingual spacefor tip up/r/and a more posterior palatal constriction for tip down/r/, which was also discussed by Espy-Wilson et al. (2000).

Extending the front cavity – and thus increasing its volume – could also be achieved through the formation of a separate lip protrusion channel (Espy-Wilson et al., 2000). Yet, to the best of our knowledge,trading relationsinvolving lip protrusion have yet to be investigated, which is perhaps due to the lack of available lip data, as Espy-Wilson et al. (2000) pointed out.

2.9 Labiodental variants

Labiodental articulations of /r/, i.e., involving the lower lip and the upper teeth such as [V], are predominantly associated withAnglo-English. The earliest known commentaries on labiodental-like variants inAnglo-Englishdate back to the mid-1800s (for a diachronic review of labiodentalisation, see Foulkes & Docherty, 2000). Up until the early 2000s, labiodentalisation was dismissed as a speech defect or an infantilism – due to its presence as a development feature in children acquiring English (Kerswill, 1996; Knight et al., 2007) – or as an affectation of upper class speech (Foulkes & Docherty, 2000). For example, Jones (1956) treated the labiodental variant as ‘defective’ and suggested strategies for its correction (as cited in Armstrong & Pooley, 2013). However, Foulkes and Docherty (2000) presented evidence to suggest that not only are perceptions of labiodental/r/changing, particularly in the popular media, but[V] is now a relatively widespread feature in non-standard south-eastern accents of England, which was also suggested by Wells (1982). Indeed, as Armstrong and Pooley (2013) noted, where the labiodental variant was once stigmatised as defective, it is now treated with greater tolerance to such an extent that ‘many parents may now be less ready to correct this variant as defective in their children’s speech’ (p. 142).

Furthermore, Foulkes and Docherty (2000)’s review of dialectological studies indicated that labiodentalisation is spreading from its south-eastern epicentre to other urban accents across England. Instances of[V]have been noted in several areas outside the capital including Milton Keynes, Reading, Hull (Williams & Kerswill, 1999), Norwich (Trudgill, 1974, 1988, 1999b),

Derby (Foulkes & Docherty, 2000), Leeds (Marsden, 2006), Middlesborough (Llamas, 1998) and Newcastle (Foulkes & Docherty, 2000). Foulkes and Docherty (2000) hypothesised that[V]may be spreading as part of a general levelling process which is currently occurring inAnglo-English.

This levelling process is believed to have originated in non-standard south-eastern varieties, which according to Foulkes and Docherty (2000), enjoys sociolinguistic dominance in young people across urban areas of England. This accent levelling typically affects consonants and the most famous features include th-fronting,/l/-vocalisation and/t/-glottaling. As Foulkes and Docherty (2000) pointed out,/r/-labiodentalisation may well be part of this same general levelling process.

While sociolinguistic factors are no doubt at play, few phonetic accounts as to why labioden-tal variants are rapidly emerging currently exist. It is generally implied that labiodenlabioden-tal variants have emerged by speakers retaining the labial component of/r/at the expense of the lingual one (Docherty & Foulkes, 2001; Foulkes & Docherty, 2000; Jones, 1972), although articulatory data is lacking. This proposition would imply that the lip posture for/r/is labiodental, i.e., produced with an approximation between the lower lip and the upper front teeth, regardless of whether or not there is an accompanying lingual gesture, which cannot currently be confirmed due to the lack of articulatory data. Docherty and Foulkes (2001) hypothesised that this change in progress from[ô]to[V]may be the result of the heavy visual prominence of the labial gesture for/r/, which may have led to the labial taking precedence over the lingual articulation. Lindley and Lawson (2016) observed one participant who produced labiodental/r/with no observable tongue body gesture. However, another participant presented labiodentalisation accompanied by a tip up tongue configuration, leading them to suspect that the change in progress from[ô]

to[V]may be phonetically gradient, in line with Docherty and Foulkes (2001)’s hypothesis.

Phonetic analyses of labiodental variants are few and far between and generally do not extend much beyond auditory accounts. Foulkes and Docherty (2000) and Marsden (2006) rated the perceptual quality of/r/on a 4-point auditory scale according to the degree of alveolar or labial articulation. However, Foulkes and Docherty (2000) also included a spectrographic and formant analysis of labiodentalAnglo-English/r/, which was probably the first study to do

2.9. Labiodental variants 71

so. They found that while energy in the higher frequencies beyond F3 is relatively weak for alveolar/r/, in labiodental/r/, high frequency energy is much clearer. Like in other studies, they categorised alveolar/r/as having a low F3 in close proximity to F2 (at around 1 700 Hz).

Labiodental/r/, in contrast, had a markedly higher F3, at around 2 200 Hz. They observed a clear correlation between their auditory index score and their acoustic measurements: variants which gave the auditory impression of[V]had higher F3 values. Foulkes and Docherty (2000) argued that this result is expected as we would predict articulations lacking retroflexionor bunchingof the tongue to result in higher F3 values.

Exposure to labiodental variants without a canonically low F3 may have resulted in a shift in the perceptual weighting of/r/in England. Somewhat unexpected differences have been observed in the perception ofapproximants betweenAmerican EnglishandAnglo-English listeners. In Dalcher et al. (2008), American and English participants judged whether copy-synthesised sounds with manually adjusted formant values were more like /r/ or /w/. A significant difference was observed for a stimulus which had a third formant typical of /r/

(1 682 Hz) and second formant typical of /w/ (725 Hz). American speakers identified this stimulus as/r/90% of the time, whileAnglo-Englishspeakers only identified it as/r/59% of the time. Dalcher et al. (2008) suggested that the reason for such a disparity may be due to the exposure to labiodental variants without a canonically low F3 inAnglo-Englishlisteners.

The increase in/r/variability with respect to its third formant may have served to catalyse a cue-shift from F3 to F2 in the perception of the/r/-/w/contrast. AsFigure 2.5suggests, apical productions of/r/contrast with/w/both with respect to F2 and F3. However, F3 is no longer contrastive in labiodental productions. As a consequence, Dalcher et al. (2008) speculated that a low F3 alone is no longer a sufficient cue to distinguish/r/from/w/inAnglo-Englishand that the F2 boundary between/r/and/w/may have become sharper inAnglo-Englishspeakers.

As such, a token with a low, [w]-like F2 value would be perceived as/w/by Anglo-English listeners even when accompanied by a low[ô]-like F3.

Figure 2.5:Formant contrasts between/r/and/w/pronunciation variants based on the formant values presented in Dalcher et al. (2008).

2.10 Chapter conclusion

The review of existing work presented within this chapter has indicated that despite the vast array of existing phonetic studies, our understanding of English/r/is still incomplete, particu-larly concerning its production innon-rhoticEnglishes and the accompanying labial gesture.

It has been well-documented inrhoticEnglishes that the post-alveolarapproximantmay be produced with a variety of different tongue shapes from tip upretroflexto tip downbunched.

Although tongue shape is generally thought to be speaker-specific (at least inAmerican En-glish), variation may be conditioned by coarticulation, syllable context, sociolinguistic factors and perhaps even by speaker physiology. Despite the diversity of possible tongue shapes, the acoustic profile of post-alveolar /r/ is remarkably consistent and is characterised by a particularly low third formant, usually in the frequency region which is normally occupied by F2. Articulatory-acoustic models have associated this low F3 with a large volume front cavity. The different possible tongue shapes for post-alveolar/r/may result in differing sized

2.10. Chapter conclusion 73

front cavities. To obtain a stable acoustic output across post-alveolar/r/variants, speakers may make systematic trade-offs between the articulatory manoeuvres available to them which reciprocally contribute to the lowering of F3. Possible manoeuvres may include modifications to the size of thesublingual space, to the place and length of the lingual constriction and to the length of the lip protrusion channel. If atrading relationinvolving the lips and tongue exists, it is possible that systematic differences in lip protrusion may be observed across the possible tongue shapes associated with/r/, which has yet to be examined.

The lips seem to play an important role in the production and perception of/r/in Anglo-Englishbecause labiodental variants are becoming increasingly common. Exposure to these variants may have had an effect on the perception of/r/, particularly with regards to the relative importance of F3 as an acoustic cue. It is thought that labiodental/r/may have emerged due to the visual prominence of the lips in the ‘standard’ post-alveolar variant, although no detailed phonetic account of the lips for/r/currently exists for any variety of English. As a result, the contribution of the lips to both the production and to the perception of/r/inAnglo-English will be investigated in this thesis.