Sound Pressure Level, dBA, Sound Dose, Safe Listening
A sound wave is a longitudinal wave that propagates by displacing differences in force or pressure from one place to another.
Sound Pressure Level is logarithmic (nonlinear) and is generally expressed in decibels measured using A-weighting network - hence dBA.
Sound Dose is the total dBA received during a specified period e.g. daily, weekly.
Duration of safe listening time has a nonlinear relationship with dBA
Depends on the level (loudness), duration (time period) and frequency of exposure through audio or ambient sources.
For example : Weekly safe listen time decreases from 40 hrs at 80 dBA to 10 hrs at 86 dBA to 75 mins at 95 dBA to 4.5 mins at 107 dBA
Safe Listening Times can be surprisingly low for some everyday sounds
Jet taking off
dB (Safe Listen mins)
References: World Health Organization, US Centers for Disease Control and Prevention, US National Institutes of Health (National Institute of Deafness and other Communication Disorders), US Environmental Protection Agency