Auditory temporal processes in normal-hearing individuals and in patients with auditory neuropathy.
OBJECTIVE
To study objectively auditory temporal processing in a group of normal hearing subjects and in a group of hearing-impaired individuals with auditory neuropathy (AN) using electrophysiological and psychoacoustic methods.


METHODS
Scalp recorded evoked potentials were measured to brief silent intervals (gaps) varying between 2 and 50ms embedded in continuous noise. Latencies and amplitudes of N100 and P200 were measured and analyzed in two conditions: (1) active, when using a button in response to gaps; (2) passive, listening, but not responding.


RESULTS
In normal subjects evoked potentials (N100/P200 components) were recorded in response to gaps as short as 5ms in both active and passive conditions. Gap evoked potentials in AN subjects appeared only with prolonged gap durations (10-50ms). There was a close association between gap detection thresholds measured psychoacoustically and electrophysiologically in both normals and in AN subjects.


CONCLUSIONS
Auditory cortical potentials can provide objective measures of auditory temporal processes.


CONCLUSIONS
The combination of electrophysiological and psychoacoustic methods converged to provide useful objective measures for studying auditory cortical temporal processing in normals and hearing-impaired individuals. The procedure used may also provide objective measures of temporal processing for evaluating special populations such as children who may not be able to provide subjective responses.
Michalewski
Henry J
HJ
Department of Neurology, University of California, 150 Med. Surge I, Irvine, CA 92697-4290, USA.
Starr
Arnold
A
Nguyen
Tin Toan
TT
Kong
Ying-Yee
YY
Zeng
Fan-Gang
FG
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001303:Auditory Cortex / Q000503:physiopathology*; D001304:Auditory Diseases, Central / Q000503:physiopathology*; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019986:Persons with Hearing Disabilities; D011571:Psychoacoustics; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012737:Sex Factors; D013997:Time Factors