Tracking and glimpsing speech in noise: Role of fundamental frequency

Abstract

Listeners with normal hearing can communicate successfully in noisy and reverberant conditions that distort temporal and spectral cues in the speech signal. Recent work has sought to identify auditory grouping processes that contribute to this ability. One property that has received attention is the fundamental frequency of voicing (F0). During voiced speech the pulsing of the vocal folds gives rise to a pattern of amplitude modulation in the waveform and harmonicity in the spectrum. When two or more voices compete for the attention of the listener, momentary differences in F0 can contribute to voice segregation in at least three ways. First, periodicity or harmonicity in the composite signal provides a basis for grouping together signal components that stem from a target voice. Second, waveform interactions generate moment-to-moment fluctuations in the signal-to-noise ratio that enable listeners to ‘‘glimpse’’ the acoustic features of the target voice. Third, time-varying changes in F0 provide a basis for tracking properties of the voice over time. The contributions of each of these processes to the perceptual segregation of speech from competing sounds will be reviewed. [Work supported by NIH/NIDCD.]