Abstract:
The Auditory Steady-State Response (ASSR) has gained popularity as an alternative
technique for objective audiometry but its use in less severe degrees of hearing loss has
been questioned. The aim of this study was to investigate the usefulness of the ASSR in
estimating moderate degrees of hearing loss. Seven subjects (12 ears) with moderate
sensorineural hearing loss between 15 and 18 years of ages were enrolled in the study. 48
behavioural and ASSR thresholds were obtained across the frequencies of 0.5, 1, 2, and 4
kHz. ASSR thresholds were determined using a dichotic multiple frequency recording
technique. Mean threshold differences varied between 2 and 8 dB (±7-10 dB SD) across
frequencies. The highest difference and variability was recorded at 0.5 kHz. The frequencies
1 – 4 kHz also revealed significantly better correlations (0.74 – 0.88) compared to 0.5 kHz
(0.31). Comparing correlation coefficients for behavioural thresholds less than 60 dB and 60
dB and higher revealed a significant difference. 86% of ASSR thresholds corresponded
within 5 dB of moderate to severe behavioural thresholds compared to only 29% for mild to
moderate thresholds in this study. The results confirm that the ASSR can reliably estimated
behavioural thresholds of 60 dB and higher, but due to increased variability caution is
recommended when estimating behavioural thresholds of less than 60 dB, especially at 0.5
kHz.
