Seminars in Hearing Research at Purdue
Students, post-docs, and faculty with interests in all aspects of hearing meeting weekly to share laboratory research, clinical case studies, and theoretical perspectives. Topics include basic and translational research as well as clinical practice. Participants are welcome from all of Purdue University including Speech, Language, and Hearing Science (SLHS), Biology (BIO), Biomedical Engineering (BME), Mechanical Engineering (ME), and Electrical Engineering (EE). Seminars provide an ideal venue for students to present their work with a supportive audience, for investigators to find common interests for collaborative efforts, and for speakers from outside Purdue to share their work. This seminar is partially supported by the Association for Research in Otolaryngology.
2020-2021 Talks
Zoom Meeting: 10:30-11:20 am
Thursday, January 28, 2021
Title: Effects of Masker Modulation Spectra and Fine Structure on Consonant Confusions
Speaker: Vibha Viswanathan, Ph.D. Student, Weldon School of Biomedical Engineering (Heinz Lab)
Zoom Info: https://purdue-edu.zoom.us/j/93590477873?pwd=TlZuZzJyZUJ4OEVwRnAzc0laZFowdz09
Meeting ID: 935 9047 7873
Passcode: 033718
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).
