Figure 13.

(A) CAP waveforms in response to 2 kHz tone burst stimulation in three ears with acoustic neurinoma. Depending on the individual case as well as on stimulus intensity, broad characteristic waveforms or nearly normal CAPs can be found. It appears that the CAP waveform is not consistently abnormal in acoustic neurinoma ears. (B) Narrow band AP waveforms in acoustic neurinoma ears. From dominantly monophasic NAPs in the left series to strictly biphasic narrow band responses in the right series, reminding us of a sensorineural hearing loss, the relationship to the CAP waveforrn is clear. From Eggermont et al. (1980).