Noise levels required to mask stimuli used in auditory brainstem response testing.

The levels of noise necessary to effectively mask the stimuli commonly used in auditory brainstem response (ABR) tests were determined. The relative masking level (RLM) of twenty normally-hearing volunteers was measured behaviourally using ipsilaterally presented unfiltered noise in the presence of ABR stimuli. The upper limit for RLM was found to be typically 30 dB above the stimulus level when the stimulus was calibrated in dBnHL to ISO 389-6 (2007) and the noise was measured in dBSPL. This value is recommended when calculating the level of noise necessary to prevent cross-hearing during ABR testing.