Acoustic trauma, also known as acoustic shock, can occur when a person is subjected to an extremely loud noise or series of loud noises such as gun shots, explosions or shouting at very close proximity.
If there is no protection to the ears, then the acoustic shock from the loud noise can cause irreparable hearing damage depending on the severity of the injury such as a perforated eardrum.
In the United Kingdom, there has been an uptake in cases of acoustic trauma from call centre workers as this industry has grown in size, even though since 1991 major manufacturers of telephone headsets have had to place noise limiters on them when a noise through the headset goes above 118 dB.
When a conversation or sound hits 118 dB or higher, the headset should not transmit the sound to the wearer of the headset. However, not all manufacturers or headsets have noise limiting features, particularly cheaper models or VOIP (Internet phone headsets) so call centre workers are at particular risk of acoustic shock if the person they are ringing shouts loudly or a headset malfunctions and causes sharp, loud feedback.