Frequency specificity of human auditory brainstem responses as revealed by pure-tone masking profiles.

The frequency specificity of the auditory brainstem response (ABR) was examined by means of pure-tone masking profiles using click, 4000-Hz, and 1000-Hz filtered-click stimuli. Simultaneous pure-tone maskers were presented at one-half octave intervals around stimulus center frequency. Masking profiles at two intensities (60 and 40 dB SL) were obtained by measuring both latency and amplitude shifts in wave V as a result of the discrete-frequency maskers. Both latency and amplitude analyses showed masking profiles at 40 dB SL that were narrow and centered around stimulus frequency, whereas profiles at 60 dB SL showed high-frequency spread of the cochlear excitation area.