Risk of acquiring hearing loss

Hearing loss (Friday, 17 September, 2021)

This week we had a very interesting session about the ear, hearing, and hearing loss from dr. Ir. Jan A.P.M. de Laat (clinical physicist and audiologist at the Leiden University Medical Center) and one of the lecturers of Sound Education Nederland.

One thing we all know but often neglect is the risk of acquiring hearing loss due to too loud sounds (rehursals with a band, orchestra, or going to a concet).

According to Dutch laws for working conditions it is allowed to work for a maximum of 8 hours at 80dB SPL (about the level on which I calibrated by studio monitors), which still is quite loud to my ears. Higher levels and longer duration give greater risk for hearing loss.

According to this law each doubling of sound pressure (that is, every increase of 3dB) implies a 50% decrease of the time allowed to be exposed.

80 dB SPL = 8 hours
83 dB SPL = 4 hours
86 dB SPL = 2 hours
89 dB SPL = 1 hour
92 dB SPL = 30 minutes
95 dB SPL = 15 minutes
98 dB SPL = 7.5 minutes
101 dB SPL = 3.75 minutes

Think about this.

If you are mixing in a live situation with 101 dB SPL then you only can watch the concert (mix the concert) for few minutes! In the last band that I played (Recover) I sometimes measured sound pressure levels during 2-3 hour rehursals and levels above 100dB were no exception.  Not precautions taken.

See also: The business of silence: is there a hidden cost to noise cancelling? (The Guardian)