Acoustic shock

'Acoustic shock' is a term used in connection with incidents involving exposure to short duration, high frequency, high intensity sounds through a telephone headset. Some sources suggest that these incidents are associated with a range of physiological and psychological symptoms that have been reported amongst headset wearers. It has not been established whether the reported symptoms are caused directly by exposure to these unexpected sounds. There is no clear single cause of these incidents, but one cause may be interference on the telephone line. Although call handlers may be shocked or startled by the sounds, exposure to them should not cause hearing damage as assessed by conventional methods.

Since 1991, major manufacturers have incorporated an acoustic limiter in the electronics of their headsets to meet the requirements of the Department of Trade and Industry (DTI) specification 85/013. In the UK, this limiter ensures that any type of noise (eg conversation, short duration impulses) above 118 dB is not transmitted through the headset.

HSE is aware that 'acoustic shock protection' and 'headset noise limiter' devices are being brought to market, but is not in a position to comment on any of these devices at this time.

HSE considers that, in general, call handlers' daily personal noise exposure is unlikely to exceed the 80 dB lower exposure action value defined in the Control of Noise at Work Regulations 2005, provided good practice in the management of noise risks is followed. Call handlers should be encouraged to report to management exposure to acoustic shock incidents and management should keep a record of these reported events.

Updated February 2008