Hearing standards Hearing loss

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human hearing extends in frequency 20-20,000 hz, , in amplitude 0 db 130 db or more. 0 db not represent absence of sound, rather softest sound average unimpaired human ear can hear; people can hear down -5 or -10 db. 130 db represents threshold of pain. ear doesn t hear frequencies equally well; hearing sensitivity peaks around 3000 hz. there many qualities of human hearing besides frequency range , amplitude can t measured quantitatively. many practical purposes, normative hearing defined frequency versus amplitude graph, or audiogram, charting sensitivity thresholds of hearing @ defined frequencies. because of cumulative impact of age , exposure noise , other acoustic insults, typical hearing may not normative.








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