Threshold Detection Using the Auditory Steady-State Response and the Tone Burst Auditory Brain Stem Response
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- Category: Vol. 81, December 2013
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Threshold Detection Using the Auditory Steady-State Response and the Tone Burst Auditory Brain Stem Response, SALWA M. ABDEL LATIF, HODA I. ABUMOUSSA and SOHA M. HAMADAA
Abstract
Background: Although objective diagnostic methods tend to dominate modern medical science, behavioral pure-tone audiometry (PTA) remains the golden standard for identifying hearing threshold levels. The tone burst auditory brain stem response (TB ABR) is a series of electrical potentials that are recordable from the scalp to give frequency-specific estimates of hearing level. A more recent method, the auditory steady-state response (ASSR) has become more and more important as an alternative to objective audiometry. Both the ABR and the ASSR provided reasonably accurate predictions of behav-ioral threshold across hearing loss subjects.
Objectives: Comparing the thresholds of tone burst audi-tory brainstem response (TB-ABR) and auditory steady-state response (ASSR) in adult in relation to pure tone thresholds.
Methodology: Forty adult subjects divided into three groups, normal hearing, moderate SNHL and severe SNHL. All subjects in this research were submitted to the following: Full history taking. Otologic examination. Basic audiological evaluations (Pure tone audiometry, Speech audiometry & Immittacemetry). Tone burst ABR recorded using 500Hz and 4000Hz stimulus and ASSR stimulus using carrier frequencies 500Hz and 4000Hz.
Results: In normal hearing group, ASSR thresholds are closer to PTA thresholds than TB thresholds, 500Hz results are better than 4000Hz results. In moderate hearing loss group ASSR and TB thresholds are approximated to PTA thresholds but still the ASSR thresholds are closer to PTA thresholds than TB thresholds. In severe hearing loss group, TB and ASSR thresholds show the best level of prediction of PTA thresholds. In normal hearing group, correlation between PTA and ASSR thresholds showed a statistically significant corre-lation at 500Hz only while correlation between PTA and Tone Burst thresholds showed a statistically significant correlation only at 4000Hz. A statistically significant correlation was found at 500Hz; between PTA and ASSR thresholds and between ASSR and Tone Burst thresholds in moderate hearing loss group. A statistically significant correlation was found at 500 and 4000Hz between PTA and ASSR thresholds, be-tween PTA and Tone Burst thresholds and between ASSR and Tone Burst thresholds in severe hearing loss group.
Conclusion: In normal hearing both TB ABR and ASSR testing show poor prediction of PTA thresholds. ASSR thresh-olds are better to estimate PTA thresholds than TB ABR thresholds in normal and moderate SNHL. Both ASSR and TB ABR thresholds showed a significant correlation with PTA that increases with the increasing severity of hearing loss.