Acoustic trauma and acoustic shock

Acoustic trauma and acoustic shock are not the same thing. Acoustic trauma is the immediate and permanent hearing loss that can result from exposure to peak impulse or explosive noise that exceeds the exposure standard for noise, which is140dB(C). It is very often associated with intense pain and, in some cases, the sound pressure can rupture the eardrum.

Acoustic shock incidents are sudden, unexpected loud noises, meaning acoustic shock injuries are not caused by hazardous noise, but by a sudden rise in the noise levels.

Acoustic shock symptoms

The effect on individuals can vary greatly for the same increase in sound level.

Immediate symptoms can include:

  • a feeling of fullness in the ear
  • burning sensations or sharp pain around or in the ear
  • numbness, tingling or soreness down the side of face, neck or shoulder
  • nausea or vomiting
  • dizziness
  • tinnitus and other head noises, such as eardrum fluttering.

Later symptoms can include:

  • headaches
  • fatigue
  • feeling off-balance
  • hypersensitivity to noise, i.e. a sensitivity to previously tolerated sounds such as loud voices, television and radio
  • anxiety

Control measures

Control measures to eliminate or minimise the risk of acoustic shock include:

  • providing high quality headsets with acoustic shock protection devices
  • giving prompt attention to damaged equipment and network faults (the equipment or network supplier or an acoustic specialist should be contacted if necessary)
  • ensuring the proper fitting, use and maintenance of headsets
  • reducing background noise in the room
  • providing information and training on how to detect warning sounds for example, cordless phones being used too close to the base station at the customer end
  • training on warning sounds should also prepare operators to know when to remove headsets as quickly as possible, where necessary
  • with hotdesking work, ensuring workers turn the headset volume down as soon as possible after a changeover
  • considering work organisation issues, such as unreasonable or unrealistic performance pressures or demands, which may cause tension and distress
  • preventing mobile phones from being used in call centres.