Frequency-Specific Auditory Brainstem Responses to Clicks Masked by Notched Noise

Abstract

Frequency-specific auditory brainstem responses were recorded as a function of the intensity of a click masked by notch-filtered white noise (i.e. band-stop-filtered). The bandwidth of the notch was fixed at five-thirds octave and the center frequency was 0.5, 1.0, 2.0 or 4.0 kHz. For normally hearing subjects the latency of the main peak in the responses is increasing with decreasing center frequency of the notch and with decreasing click intensity. At a click sensation level of 60 dB, the mean of 7 subjects' peak latency was 6.7 ms for the center frequency 4.0 kHz and 10.2 ms for the center frequency 0.5 kHz. The thresholds derived from the frequency-specific responses were within 20 dB above the subjective thresholds of audibility of the clicks as heard when masked by notched noise.

Key Words:

• Auditory brainstem response
• Notch-noise masker