It is known that staying at high sound levels for long periods of time ruins the hearing apparatus forever.
As the limit of an average 90 dB per 8 hours of exposition is exceeded we must start using protection aids, above 135 dB protections are mandatory because pain and hear damage are instantaneous.
There are two factors to remember: the first is that the higher the sound level the less the time we can listen continously to the sounds themselves and the longer the time we must remain in a quiet place to recover; the second is that our hearing system is much more sensitive to mid-high frequencies (250-4000 Hz octaves – from the third F on the piano keyboard up) than to bass (32-125 Hz octaves – from the lowest key up to the third F). Mid-high frequencies are the most important to understand human speech and should be saved to avoid premature hearing loss and a needless handicap.

Next is a graph showing recommended time limits for higher sound levels when listening to music (which technically is defined as a sound signal with many pure tones and impulses)

Livelli ammessi

We can see how raising the volume the permitted time shortens. A phonometer can be very useful to understand and hence to know how to defend oneself: the simpler ones give an average at 500 Hz, use the unweighted values to compare them with the graph.
As generic terms of comparison 80 dB can be reached in a very noisy office or can be found in a noisy street: you can hardly use the phone at this sound level; 90 dB are generated by a 25 element orchestra or by a heavy diesel truck passes at 10 m from you while 100 dB can be heard and passed in a disco or by the firecrackers.

The conclusion is that hearing protections are very important for studio, live and broadcast engineers and all musicians as well because exceeding the above limits gives permanent hearing loss.
Nowadays research as developed good protections that give the same result on all frequencies and lower sound levels up to 12 dB.