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.