Effects of Aging on Perceptual and Electrophysiological Responses to Acoustic Pulse Trains as a Function of Rate

Purpose As pulse rate increases beyond a few hundred Hertz, younger normal-hearing (NH) participants' ability to encode temporal information in band-limited acoustic pulse trains decreases, demonstrating a rate limitation in processing rapid temporal information. Rate discrimination abilities, however, have yet to be investigated in older NH participants—a population that experiences age-related temporal processing deficits. It was hypothesized that age-related temporal processing deficits lead to decreased temporal rate discrimination abilities in older compared with younger NH participants, which could be observed in both perceptual and electrophysiological measurements. Method Fifteen younger and 15 older NH participants were presented acoustic pulse trains with a 4-kHz center frequency and 1-kHz bandwidth at 75 dB SPL monaurally. The pulse rate was 80, 200, or 400 Hz. Just noticeable differences were obtained using an adaptive procedure that instructed the participants to identify the pulse train with...