Subcortical representation of voice onset time (Tamura et al., 2019)

<b>Purpose:</b> The purpose of this study was to investigate whether speech perception would reflect small latency changes in subcortical speech representation.<b>Method:</b> Twelve native Japanese listeners participated in the experiment. Those listeners participated in speech identification task and auditory brainstem response (ABR) measurement using /d/–/t/ continuum stimuli varying in voice onset time (VOT) with manipulation of the amplitude of initial noise (consonant) portion, the duration of which corresponded to VOT.<b>Results:</b> Increasing the noise portion amplitude lengthened subcortical representation of VOT, which is the latency difference between ABRs synchronizing to the onsets of initial noise and following periodic (vowel) portions (VOT_ABR) and made listeners likely to perceive the stimuli with ambiguous VOT as a voiceless stop /t/. In addition, the amount of VOT_ABR lengthening was close to that of the VOT boundary shortening.<b>Conclusion:</b> A few milliseconds of difference in subcortical speech representation are important for the perception of speech sounds with ambiguous acoustic cues.<br><b>Supplemental Materials S1–S14. </b>Speech stimuli. <br>Tamura, S., Ito, K., Hirose, N., &amp; Mori, S. (2019). Effects of manipulating the amplitude of consonant noise portion on subcortical representation of voice onset time and voicing perception in stop consonants. <i>Journal of Speech, Language, and Hearing Research.</i> Advance online publication. https://doi.org/10.1044/2018_JSLHR-H-18-0102