| Popis: |
In electric response audiometry the vertex‐positive wave with latency of about 6 msec (P6), originating in the brain stem (BSR), is a sensitive and reliable indicator. It is closely related to the first response (N1) of the auditory nerve: the latency difference is constant at about 4.0 msec. As in the electrocochleogram, BSR shows both a low‐intensity and a high‐intensity branch in its latency‐intensity and its amplitude‐intensity functions, with changes of slope, breaks, or plateaus in the range from 40 to 60 dB SL. Thus brain stem audiometry, like electrocochleography, can show a “recruitment‐type response” (absence of the low‐intensity segment) in certain types of cochlear pathology. [Work supported by NINCDS.] |
