Acoustic shock

Acoustic shock is the set of symptoms a person may experience after hearing an unexpected, loud sound, called an acoustic incident, such as feedback, fax tones or signalling tones. Telemarketers and call centre employees are thought to be most at risk. People report pain and discomfort during the exposure and afterward shock, nausea, anxiety or depression, with headache, fatigue, hypersensitivity to loud noise and tinnitus lasting days, weeks or longer. How the varied symptoms arise is not established, and some literature treats it as largely psychogenic. The tensor tympani muscle of the middle ear has been proposed as involved. Prevention efforts include signal processing devices and limiting background noise, and workers have brought compensation claims.