Seminars in Hearing Research at Purdue (SHRP)

Speaker: Vibha Viswanathan (PhD candidate and F31 NIH Fellow, Weldon School of Biomedical Engineering) 
 

Effects of Masker Modulation Spectra and Fine Structure on Consonant Confusions

Date: January 28th, 2021
Time: 10:30 – 11:20 am
Location: Zoom**
Zoom Info:  contact host

Abstract:

Prominent theories of speech intelligibility suggest that modulation masking of the energy fluctuations, or envelopes, in target speech by background noise influences perception. Consistent with this notion, our previous study showed that the spectral profile of EEG-based target-envelope coding is shaped by the masker’s envelope spectrum, and in turn predicts intelligibility across diverse backgrounds. However, this envelope coding is shaped not only by cochlear envelopes, but also by fine structure (faster stimulus fluctuations), which supports scene segregation. The present study examines whether consonant confusions further inform how the temporal information in scene acoustics shapes speech perception. Online subjects from Prolific.co performed a psychophysical consonant identification task in different masking conditions. Our results show that confusion patterns differ for maskers with different envelope spectra (after matching intelligibility), consistent with variations in modulation masking. However, confusion patterns also differ between intact and envelope-vocoded speech in babble, despite these conditions having similar masker envelope spectra. Importantly, there is a greater tendency in the vocoded condition (compared to intact) to be biased towards reporting an unvoiced consonant as being heard, which suggests that fine structure conveys voicing (consistent with its role in pitch perception). These results inform future intelligibility models and assistive listening devices (e.g., cochlear implants).

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**Please e-mail the host to join the SHRP seminar mailing list. Seminar announcements and Zoom links are sent to the mailing list on a weekly basis.


The working schedule for this semester is at:

https://purdue.edu/TPAN/hearing/shrp_schedule 

The titles and abstracts of the talks are here:

https://purdue.edu/TPAN/hearing/shrp_abstracts