Noise Exposure 101

Noise exposure, present in everyday life, puts individuals at a high risk for developing hearing loss and tinnitus.  

From the American Tinnitus Association website (https://www.ata.org/understanding-facts/causes): "Exposure to loud noises, either in a single traumatic experience or over time, can damage the auditory system and result in hearing loss and sometimes tinnitus as well. Traumatic noise exposure can happen at work (e.g. loud machinery), at play (e.g. loud sporting events, concerts, recreational activities), and/or by accident (e.g. a backfiring engine.) Noise induced hearing loss is sometimes unilateral (one ear only) and typically causes patients to lose hearing around the frequency of the triggering sound trauma."

https://www.tinnitus.org.uk/noise-and-the-ear

"The ‘dosage’ of noise exposure is dependent on two main things:

1. the ‘volume’ or intensity of the noise
2. the time or duration of the exposure to that noise.

The intensity of a noise can be measured by comparing its sound pressure (the change in air pressure caused by the sound) to that of the quietest sound that can be heard. The intensity of sound is measured in decibels(dB). Decibels are what’s called a logarithmic unit, and this means that an increase of 3dB in a sound means that the sound intensity is doubled. So a sound of 88dB is twice as intense as a sound of 85dB.

Noise exposures are a combination of the intensity and the duration of the noise exposure. Most international regulations for noise exposure at work state that the loudest noise someone should be exposed to for an 8-hour working day is 85dB - roughly equivalent to a blender, or a milling machine. Now, as we saw before, a 88dB sound is twice as intense as a 85dB sound, so it follows that the maximum exposure duration should be half as much, so 4 hours. This rule of halving the maximum exposure duration for every 3dB increase (so doubling) in sound intensity is true for noises up to around 110-120dB. Above this, even a very short exposure time can be damaging."