The Auditory Steady-State Response and the Relationship between Electrophysiological and Behavioural Thresholds.

Abstract

This study examined the relationship between behavioural thresholds as measured by pure tone audiometry and electrophysiological thresholds measured by the Auditory Steady-State Response (ASSR) in children with normal hearing and sensorineural hearing loss. After being assessed, 45 children of both sexes, ranging in age from 5 to 15, were split into four groups: 10 with moderate to moderately severe sensorineural hearing loss (G2M); 10 with steeply sloping sensorineural hearing loss (G2D); 10 with profound and severe sensorineural hearing loss (G2S); and 15 with normal hearing (G1). ASSR, tympanometry, acoustic reflex testing, pure tone audiometry, and speech audiometry (SRT and SDT) were performed. The electrophysiological maximum in the group with normal hearing thresholds varied from 19 to 27 dB NA. The correlation in the group with moderate to moderately severe hearing loss was 0.42-0.74. The correlation in the steeply sloping hearing loss group was 0.68-0.94. The correlation in the group of people with profound and severe hearing loss was 0.59-0.86. The normal hearing group's mean differences in ASSR threshold and audiometric threshold ranged from -0.3 to 12 dB, in the moderate and moderately severe hearing loss group from -9 to 2 dB, in the steeply sloping hearing loss group from 1.4 to 7.5 dB, and in the severe and profound hearing loss group from -0.40 to 8.5 dB. As expected, there was no strong relationship between behavioural and electrophysiological thresholds in the group with normal hearing. But in children with hearing loss, there was a strong correlation between electrophysiological and behavioural thresholds; this relationship was especially evident in children with severe and profound hearing loss and those with steeply sloping hearing loss.