To assess temporal integration across frequencies in individuals with normal hearing and in individuals with flat and sloping cochlear hearing loss, absolute threshold for tones were measured as a function of duration. Tone detection threshold was measured in both the groups using sinusoidal stimulus of three different frequencies 250 Hz, 1000 Hz and 4000 Hz with duration varying from 2ms to 200ms, 10 to 200ms and 2 ms to 200 ms respectively. The results revealed that, In normal hearing participants for every doubling of duration threshold decreased by approximately 3dB at 250 Hz and 1000Hz whereas at 4kHz was 2.2 dB. In cochlear hearing loss participants shown an abnormal pattern of temporal integration. Participants with flat hearing loss showed a small reduction in temporal integration than normal hearing participants. Whereas participants with sloping hearing loss showed reduced amount of temporal integration than normal hearing and flat hearing loss participants. At lower frequency majority of listeners showed similar performance as normal hearing listeners. But as frequency increases performed worsened. In general majority of cochlear hearing performed better at 250 Hz, because of use of spectral splatter cues at other frequencies.
Keywords: Temporal Integration,Cochlear Hearing loss, Frequency