Derived brain stem responses by means of pure-tone masking.

In order to demonstrate the possibility of deriving narrow-band responses, investigations using simultaneous pure-tone masking at frequencies of 1 and 0.5 kHz were carried out. Constant and reproducible derived responses were obtained at both masker frequencies within the following latency ranges: w6 (masker frequency 1 kHz) from 7.7 to 9.9 msec and w7 (masker frequency 0.5 kHz) from 9.2 to 11.2 msec at intensities of 70-20 dBSL. The agreement of our results with those obtained with the high-pass noise-masking technique permits us to ascribe our narrow-band responses (w6, w7) to the corresponding frequency regions around 1 and 0.5 kHz along the cochlear partition. This method is suitable for deriving frequency-specific responses without any sophistication.