Emergence of noise-induced hearing loss can be divided into two phases. The first phase is characterized by the Temporary Threshold Shift (TTS). Slight loss of hearing occurs after exposure to noise which is completely
withdrawn after a period of rest. It is recognized by light distinctive "ringing in the ears" and occurs after, for
example, listening to loud music. Recovery time can take up to 48 hours, depending on the duration of exposure to
noise. This damage can be considered as ear fatigue and many studies show that there is no damage to the sensory cells.