National Vision and Hearing Screening Protocols (revised 2014)

The level of hearing is defined as the lowest decibel hearing level at which a response reliably occurs. The tones to be used are 1–2 second duration pure-tone stimuli at 500, 1000, 2000 and 4000 Hz. Note that the minimum levels to be tested to are: 25 dB at all test frequencies … ................
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