The influence of auditory acuity on acoustic variability and the use of motor equivalence during adaptation to a perturbation.
OBJECTIVE
The aim of this study was to relate speakers' auditory acuity for the sibilant contrast, their use of motor equivalent trading relationships in producing the sibilant /∫/, and their produced acoustic distance between the sibilants /s/ and /∫/. Specifically, the study tested the hypotheses that during adaptation to a perturbation of vocal-tract shape, high-acuity speakers use motor equivalence strategies to a greater extent than do low-acuity speakers in order to reach their smaller phonemic goal regions, and that high-acuity speakers produce greater acoustic distance between 2 sibilant phonemes than do low-acuity speakers.


METHODS
Articulographic data from 7 German speakers adapting to a perturbation were analyzed for the use of motor equivalence. The speakers' produced acoustic distance between /s/ and /∫/ was calculated. Auditory acuity was assessed for the same speakers.


RESULTS
High-acuity speakers used motor equivalence to a greater extent when adapting to a perturbation than did low-acuity speakers. Additionally, high-acuity speakers produced greater acoustic contrasts than did low-acuity-speakers. It was observed that speech rate had an influence on the use of motor equivalence: Slow speakers used motor equivalence to a lesser degree than did fast speakers.


CONCLUSIONS
These results provide support for the mutual interdependence of speech perception and production.
Speech Communication Group, Massachusetts Institute of Technology, Cambridge, MA, USA. jana.brunner@uni-potsdam.de
Jana
J
Brunner
Satrajit
S
Ghosh
Philip
P
Hoole
Melanie
M
Matthies
Mark
M
Tiede
Joseph
J
Perkell
D000161:Acoustic Stimulation; D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D005260:Female; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008046:Lip / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010159:Palate / Q000502:physiology; D010700:Phonetics; D013060:Speech / Q000502:physiology*; D013063:Speech Discrimination Tests; D013065:Speech Intelligibility / Q000502:physiology*; D014059:Tongue / Q000502:physiology