Threshold shift temporary

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. 

Double hearing protection A combination of both earplug and earmuff types of hearing protection devices is required for employees who have demonstrated temporary threshold shift during audiometric examination and for those who have been advised by a medical doctor to wear double protection in work areas that exceed 104 dBA. 

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. 

There are three principal categories of NHL (1) temporary threshold shift (TTS), (2) permanent threshold shift (PTS), and (3) acoustic trauma. TTS occurs when exposure to sound damages the organ of Corti and its receptor cells. However, if the exposure is of relatively short duration, hearing sensitivity returns to preexposure levels after a recovery period (Brauer 1994). PTS, on the other... 

---