Accession Number : AD0714204

Title :   On the Relation Between Temporal Envelope Patterns at Two Different Points in the Cochlea.

Descriptive Note : Technical rept. Apr-Oct 70,

Corporate Author : STANFORD UNIV CALIF HEARING SCIENCE LABS

Personal Author(s) : Schubert,Earl D. ; Nixon,James C.

Report Date : NOV 1970

Pagination or Media Count : 19

Abstract : A series of experiments was run to determine to what extent the auditory system can tell whether two envelope patterns at two different points on the basilar membrane are from the same random source or from two different sources. The signals were fabricated by modulating two carriers with bands of noise; sometimes with the same noise modulating both carriers, sometimes with two independent noises. The subjects were given continuous signals with a short burst inserted during an observation interval. They were asked to report whether the pair was the same as the signal or different. The only change made during the insert was a shift from the same modulator for the two carriers to two different modulators on half the trials. The signal bursts were either 25 msec, 50 msec or 100msec in length. One carrier frequency remained at 350Hz, the other was varied up to a separation of one octave. Subjects could not tell whether the envelope patterns at the two locations were related or unrelated for any of the carrier spacings used at any of the durations. With the same kind of signals presented to the binaural system, i.e., with one modulated carrier fed to one ear and one to the other, the subjects could tell with reasonable accuracy when the envelope at one ear was correlated with that at the other. Performance was very good when the carrier frequency was the same at the two ears, and continued well above chance when the two carriers differed in the two ears by as much as one octave. (Author)

Descriptors :   (*AUDITORY PERCEPTION, TESTS), NERVE CELLS, LOW PASS FILTERS, BANDWIDTH, HEARING, AUDITORY SIGNALS, RESPONSE(BIOLOGY)

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE