Temporary threshold shifts, noise

Temporary threshold shift (TTS) A temporary shift in hearing threshold level that goes away after the person has been in a quiet environment for a few hours. It is confirmed by an audiogram retest following a suspected standard threshold shift (STS) after at least 14 hours away from high levels of noise. 

Exposure to noise levels of about 90 dBA for even a few minutes may induce a temporary threshold shift (change of the threshold at which sound can just be heard), lasting from seconds to hours, and which can be detected by audiometry. Temporary threshold shift (TT5) may be accompanied by noises in the ears (tinnitus) and may be a warning sign of susceptibility to permanent threshold shift (PTS) which is an irreversible deafness. 

Temporary threshold shift (TTS) Temporary loss of normal hearing level brought on by brief exposure to high-level sound. TTS is greatest immediately after exposure to excessive noise and progressively diminishes with increasing rest time. 

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