Relationship between physiological and psychoacoustical sensitivity to amplitude and frequency modulation.

Abstract

Various researchers have found a correlation between the auditory steady state response (ASSR) and corresponding behavioral measurements such as speech recognition scores [e.g., Dimitrijevic et al. (2001)]. However, relatively few studies have examined the sensitivity to small changes in amplitude and frequency modulation depths. In the present study, it was hypothesized that physiological individual differences in sensitivity to amplitude and frequency modulation depths would be reflected in corresponding psychophysical measures. Auditory steady-state responses were collected in response to amplitude- and frequency-modulated pure tone carriers (500 and 3000 Hz) in normally hearing listeners over a range of modulation depths at several different modulation rates. Participants also completed a psychophysical task in which they were asked to detect the modulated tone in a two-interval forced choice testing paradigm. The relationships between the ASSR and the psychophysical performance will be discussed.