Frequency‐difference thresholds for tones in noise for the cat: Comparison with auditory nerve responses

Abstract

Frequency‐difference thresholds for 950‐Hz tones in the presence of continuous broadband noise were obtained from three cats using a behavioral paradigm described previously [J. A. Costalupes, J. Acoust. Soc. Am. 74, 758–764 (1983)]. Four noise spectrum levels ranging from 13.5–43.5 dB SPL were used and the same signal‐to‐noise ratio was used at each noise level. The signal‐to‐noise ratio was approximately 9 dB above mean behavioral detection threshold for a 1‐kHz tone in noise for each cat. The largest frequency‐difference thresholds for each cat were noted at the lowest noise level. Frequency‐difference thresholds were approximately constant at the higher noise levels. Results will be compared with the representation of tones in noise in the responses of populations of auditory nerve fibers in the cat, which reveal rate‐change information over a similar range of stimulus intensities.