Effect of Number of Channels in Hearing Aid on Spectral Profile Analysis Threshold in Individuals with Hearing Impairment

Abstract

Auditory streaming, auditory stream segregation, or auditory scene analysis are terms used to describe the auditory system's ability to separate various sounds and group similar sounds. One of the important spectral cue that help in streaming is spectral profiling. Profile analysis tasks can be used to test how sensitive the auditory system is to the changes in spectral shapes. Spectral profile analysis thresholds are reported to be poorer in individuals with cochlear hearing loss and in the auditory neuropathy spectrum disorder(ANSD) group due to poorer spectral and temporal processing of incoming signals. Individuals decode various speech sounds using spectral information, altering the way hearing aids process the signal can improve the spectral processing in individuals with sensorineural hearing loss. The present study aims to assess and compare the spectral profile analysis threshold between 6,8 and 12-channel hearing aids across different frequencies (250 Hz, 500 Hz, 750 Hz, 1000 Hz) on individuals with mild – modetate sensorineural hearing loss. A total of twenty ears were included in the study. The spectral profile analysis threshold was assessed using the „mlp‟ toolbox, which implemented the maximum likelihood procedure in MATLAB. The study results revealed no significant difference in the spectral profile analysis threshold between 6,8 and 12-channel hearing aids in all the test frequencies. Also, the spectral profile analysis threshold is better with a 1000 Hz test frequency compared to other frequencies. This might be due to the major harmonics of the test stimuli (1000 Hz) falling in the high-frequency region and the effectiveness of the number of channels in the same region.