crowds of people at a music festival

Sound Cannons: Crowd Control and Permanent Hearing Damage

Long Range Acoustic Devices (LRADs), such as sound cannons were made for the military to control large crowds. 

They amplify a tremendous amount of sound that can reach a relatively long distance. LRADs transform electrical impulses into sound.

LRADs create very loud sounds – identical waves emerge from the [piezoelectric] transducers, and their amplitudes combine and create louder sounds.”

In the recent weeks, we have seen these LRADs being used in protests around the United States. These LRADs are very harmful for your hearing and can be extremely painful for your ears. The American Speech-Language-Hearing Association (ASHA) states that:

  • Sound emitted can reach up to 162 dB (exceeding the extremely high decibel level of a jet engine).
  • Sound emitted can significantly surpass the average 130 dB auditory threshold of pain.
  • Damage may include permanent hearing loss.
  • Damage may include migraines, vestibular symptoms, and other auditory conditions.
  • Those with pre-existing auditory injuries may be at a higher risk of harm.

LRADs’ sonic injury targets the inner ear – eardrum, hair cells, and the Corti organs. The amount of damage depends on your proximity to the LRAD. Then what can we do if we ever come across a LRAD during a large gathering? In a recent article, Experts Warn of ‘Sound Cannon’ Hearing Loss at Protest Marches, reporter Steven Reinberg suggests that when LRADs are being used, you should:

  • Go behind a brick or concrete wall to seek shelter since sound waves bounce off dense and hard surfaces.
  • Walk to the left or right of the LRAD instead of continuing to be directly in front of it while backing away to look for shelter.

And of course, earplugs may also help protect you from the permanent damage that LRADs and sound cannons can cause.