(e) Auditory fatigue appears in the 90 dB associated with whistling and buzzing in ears. Temporary deafness occurs at 4000-6000 Hz, and this effect is known as Temporary Threshold Shift (TTS), Permanent loss of hearing occurs at 100 dB due to continuous noise exposure. Under such conditions, the auditory threshold shift is called Permanent Threshold Shift (PTS). Besides chronic hearing loss, there may be instantaneous damage or acoustic trauma, which may be caused by very high intensity impulsive noise resulting from an explosion or sudden excessive noise of more than 150 dB.
While noise-induced hearing loss is permanent, it is also very preventable.  Particularly in the workplace, regulations may exist depicting maximum allowed levels of noise. This can be especially important for professionals working in settings with consistent exposure to loud sounds, such as musicians , music teachers and sound engineers .  Examples of measures taken to prevent noise-induced hearing loss in the workplace include engineering noise control, the Buy-Quiet initiative, creation of the Safe-in-Sound Award , and noise surveillance.