[Discrimination of the dynamic properties of sound source spatial location in humans (electrophysiology and psychophysics)].
The spatial resolution of human auditory system has been studied while the localization of sound source has been changed according to the different temporal patterns of interaural time delay. Two experimental procedures have been run in the same group of subjects: psychophysical procedure (the transformed staircase method) and electrophysiological one (which requires recording of mismatch negativity, the auditory evoked response component). It has been established that 1) the magnitude of the mismatch negativity reflects the extent of spatial deviance of the sound source 2) the mismatch negativity is elicited even at minimal (20 micros) interaural time delays under both temporal patterns (abrupt azimuth change and gradual sound movement at various velocities) 3) the abrupt change of the sound source azimuth results in greater mismatch negativity than the gradual sound movement does, if the interaural time delay exceeds 40 micros 4) the discrimination threshold values of the interaural delay obtained in the psychophysical procedure are greater than the minimal interaural delays that elicit the mismatch negativity, with the exception of the expert listeners who has shown no significant difference.
Al'tman
Ia A
IaA
Vaĭtulevich
S F
SF
Petropavlovskaia
E A
EA
Shestopalova
L B
LB
D000328:Adult; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D013017:Sound Localization / Q000502:physiology*; D013997:Time Factors