Perception of American English dark /l/ by normally hearing young adult women

Difficulties in decoupling articulatory gestures in L2 phonemic sequences: the case of Mandarin listeners' perceptual deletion of English post-vocalic laterals

Nonnative or second language (L2) perception of segmental sequences is often characterised by perceptual modification processes, which may "repair" a nonnative sequence that is phonotactically illegal in the listeners' native language (L1) by transforming the sequence into a sequence that is phonotactically legal in the L1. Often repairs involve the insertion of phonetic materials (epenthesis), but we focus, here, on the less-studied phenomenon of perceptual deletion of nonnative phonemes by testing L1 Mandarin listeners' perception of post-vocalic laterals in L2 English using the triangulating methods of a cross-language goodness rating task, an AXB task, and an AX task. The data were analysed in the framework of the Perceptual Assimilation Model (PAM/PAM-L2), and we further investigated the role of L2 vocabulary size on task performance. The experiments indicate that perceptual deletion occurs when the post-vocalic lateral overlaps with the nucleus vowel in terms of tongue backness specification. In addition, Mandarin listeners' discrimination performance in some contexts was significantly correlated with their English vocabulary size, indicating that continuous growth of vocabulary knowledge can drive perceptual learning of novel L2 segmental sequences and phonotactic structures.

Acoustic Characteristics of Pre- and Post-vocalic /l/: Patterns from One Southern White Vernacular English

This study examined acoustic characteristics of the phoneme /l/ produced by young female and male adult speakers of Southern White Vernacular English (SWVE) from Louisiana. F1, F2, and F2-F1 values extracted at the /l/ midpoint were analyzed by word position (pre- vs. post-vocalic) and vowel contexts (/i, ɪ/ vs. /ɔ, a/). Descriptive analysis showed that SWVE /l/ exhibited characteristics of the dark /l/ variant. The formant patterns of /l/, however, differed significantly by word position and vowel context, with pre-vocalic /l/ showing significantly higher F2-F1 values than post-vocalic /l/, and /l/ in the high front vowel context showing significantly higher F2-F1 values than those in the low back vowel context. Individual variation in the effects of word position and vowel contexts on /l/ pattern was also observed. Overall, the findings of the current study showed a gradient nature of SWVE /l/ variants whose F2-F1 patterns generally fell into the range of the dark /l/ variant, while varying by word position and vowel context.

Perception of Children's Productions of /l/: Acoustic Correlates and Effects of Listener Experience

INTRODUCTION

The aim of the current study was to examine the effect of listeners' experience with child speech and phonetic training on perceptual judgment of children's word-initial /l/ productions. The acoustic correlates of acceptable and misarticulated productions of /l/ and their relation to listeners' experience with child speech were explored.

METHODS

Three listener groups listened to children's word-initial /l/ productions embedded in monosyllabic words and judged the "/l/-likeness" of the productions using a Visual Analog Scale (VAS). Three listener groups included (a) speech-language pathologists with at least 10 years of experience (SLP group), (b) graduate students in speech-language pathology (GS group), and (c) naïve listeners with no clinical phonetics experience (NL group). Acoustic correlates (both static and dynamic measures) of listeners' perception of /l/ sounds were also investigated.

RESULTS

While mean VAS ratings did not differ significantly by listener group, the SLP group used a wider range of the VAS than the GS and NL groups. Correlational analysis between the static measure (F2-F1 values) and mean listener ratings showed that listeners tend to perceive sounds with the highest F2-F1 values more as /j/ than /l/, while those with the lowest F2-F1 value were perceived more as /w/ than /l/, especially for sounds that are in between phonemic categories. Listener ratings were not highly correlated with dynamic measures.

CONCLUSION

These results suggest that experienced listeners use the VAS more continuously than less experienced listeners to indicate perception of subphonemic features of children's productions of /l/, and that their ratings correlate with acoustic measures. Furthermore, listeners with experience with child speech and phonetic training are more sensitive to subphonemic features of children's productions of /l/, especially for misarticulated productions. This supports the clinical use of VAS for perceptual judgments of children's /l/ productions.

Formant Trajectory Patterns of American English /l/ Produced by Adults and Children

Purpose Most acoustic and articulatory studies on /l/ have focused on either duration, formant frequencies, or tongue shape during the constriction interval. Only a limited set of data exists for the transition characteristics of /l/ to and from surrounding vowels. The aim of this study was to examine second formant (F2) transition characteristics of /l/ produced by young children and adults. This was to better understand articulatory behaviors in the production of /l/ and potential clinical applications of these data to typical and delayed /l/ development. Method Participants included 17 children with typically developing speech between the ages of 2 and 5 years, and 10 female adult speakers of Southern American English. Each subject produced single words containing pre- and postvocalic /l/ in two vowel contexts (/i, ɪ/ and /ɔ, ɑ/). F2 transitions, out of and into /l/ constriction intervals from the adjacent vowels, were analyzed for perceptually acceptable /l/ productions. The F2 transition extent, duration, and rate, as well as F2 loci data, were compared across age groups by vowel context for both pre- and postvocalic /l/. Results F2 transitions of adults' /l/ showed a great similarity across and within speakers. Those of young children showed greater variability, but became increasingly similar to those of adults with age. The F2 loci data seemed consistent with greater coarticulation among children than adults. This conclusion, however, must be regarded as preliminary due to the possible influence of different vocal tract size across ages and variability in the data. Conclusions The results suggest that adult patterns can serve as a reliable reference to which children's /l/ productions can be evaluated. The articulatory configurations associated with the /l/ constriction interval and the vocal tract movements into and out of that interval may provide insight into the underlying difficulties related to misarticulated /l/.

Acquisition and Acoustic Patterns of Southern American English /l/ in Young Children

Purpose The aim of the current study was to examine /l/ developmental patterns in young learners of Southern American English, especially in relation to the effect of word position and phonetic contexts. Method Eighteen children with typically developing speech, aged between 2 and 5 years, produced monosyllabic single words containing singleton /l/ in different word positions (pre- vs. postvocalic /l/) across different vowel contexts (high front vs. low back) and cluster /l/ in different consonant contexts (/pl, bl/ vs. /kl, gl/). Each production was analyzed for its accuracy and acoustic patterns as measured by the first two formant frequencies and their difference (F1, F2, and F2-F1). Results There was great individual variability in /l/ acquisition patterns, with some 2- and 3-year-olds reaching 100% accuracy for prevocalic /l/, while others were below 70%. Overall, accuracy of prevocalic /l/ was higher than that of postvocalic /l/. Acoustic patterns of pre- and postvocalic /l/ showed greater differences in younger children and less apparent differences in 5-year-olds. There were no statistically significant differences between the acoustic patterns of /l/ coded as perceptually acceptable and those coded as misarticulated. There was also no apparent effect of vowel and consonant contexts on /l/ patterns. Conclusion The accuracy patterns of this study suggest an earlier development of /l/, especially prevocalic /l/, than has been reported in previous studies. The differences in acoustic patterns between pre- and postvocalic /l/, which become less apparent with age, may suggest that children alter the way they articulate /l/ with age. No significant acoustic differences between acceptable and misarticulated /l/, especially postvocalic /l/, suggest a gradient nature of /l/ that is dialect specific. This suggests the need for careful consideration of a child's dialect/language background when studying /l/.

Coarticulation in Catalan dark [l] and the alveolar trill: general implications for sound change

Coarticulation data for Catalan reveal that, while being less sensitive to vowel effects at the consonant period, the alveolar trill [r] exerts more prominent effects than [ł] on both adjacent [a] and [i]. This coarticulatory pattern may be related to strict manner demands on the production of the trill. Both consonants also differ regarding the relative prominence of the consonant-to-vowel anticipatory and carryover effects in VCV sequences: while [r] and [ł] exert much anticipatory coarticulation on the preceding vowel, carryover effects on the following vowel turn out to be more salient for [r] than for [ł]. These consonant-dependent differences in coarticulatory direction parallel the directionality patterns observed in related vowel assimilatory and glide insertion processes occurring in the Romance languages, in Early Germanic, in Old, Middle and Modern English, and in Arabic when the target consonant is not [ł] or [r] but a pharyngealized dentoalveolar.