Influence of Recording Time and Noise Level on the thresholds of Multiple Auditory Steady-State Response

Abstract

The influence of recording time and noise level on the precision of the hearing thresholds estimated by the auditory steady-state response (ASSR) using the multiple simultaneous stimulation technique was investigated. ASSR thresholds at four frequencies in both ears were assessed in 11 normal hearing adults and 12 hearing-impaired children at rest. The difference scores between ASSR and the behavioral hearing thresholds were compared for ASSR recordings of 16, 24 and 32 sweeps, corresponding to 5, 7.5 and 10minutes of recording time. The mean difference scores were 19.5±11.2, 17.4±10.4, 15.6±10.3dB in adults and 13.1±14.4, 12.2±14.3, 11.7±15.2dB in children after recordings for 5, 7.5 and 10minutes respectively. In adults, increase of the test duration decreased the noise level and reduced the difference score significantly, while a longer test duration led to a reduced noise level, but did not contribute to higher precision of the hearing threshold estimates by ASSR in children. In the recording of ASSR in sleeping children, it is considered that a test duration of 16 sweeps would be sufficiently long to yield the precise thresholds.