Comparison of Spectral Profile Analysis Threshold Between Children With Normal Hearing and With Cochlear Implants

Abstract

The ability of the individuals to segregate incoming sounds into separate perceptual streams is called auditory stream segregation. Spectral profiling is an important spectral cue for auditory streaming. Spectral profile analysis test is for assessing the ability of an individual to detect change in spectral profile when amplitude of one of the component of complex tone is changed. In inividuals with hearing impairement the spectral profiling ability will be affected because of the alterations in the mechanism of the basilar membrane and due to increase in the region of excitation along the membrane. Therefore, cochlear implants (CI) which are devices to restore hearing for individuals with hearing loss are expected to re-establish the spectral profiling ability of the individuals. In the present study two groups of participants were included. Group I consist of 15 children with normal hearing and group II consist of 21 children with cochlear implant. The spectral profile analysis test was assessed in two groups using the „mlp‟ toolbox, which implements the maximum likelihood procedure in the MATLAB software. The testing was done in four different frequencies (250 Hz, 500 Hz, 750 Hz and 1000 Hz). The result of the study indicates that profile analysis threshold at all four frequencies were significantly poorer in children with cochlear implant than children with normal hearing. The poorer performance in children with CI is suspected to be the result of reduced spectral resolution with cochlear implant.