The worst thing is tinnitus that generates constant ringing or noise in the nerves that is not related to anything in the environment. It is a malfunction of the hearing mechanism and the main cause is loud noise.
This can be from chain saws; music; drills; machinery; rock concerts; and so on. A friend of mine acquired it from being in the army and the guns he had to use. It is doubtful whether soldiers would be compensated for this condition when it occurs after they leave the service.
People who work with loud noise are risking their hearing and many do not know it. While it is common to have it playing in shops the assistants are unaware of the risk they are taking. Likewise, customers who have to put up with it while shopping are also in danger.
This is a general health hazard and one that governments and the medical profession should be advertising in order to prevent it causing a plague of deafness in the community. Yes! I did say deafness because my brother was in music and is driven crazy with the condition and is now deaf in one ear with reduced hearing in the other.
There is no need to play music at such a volume as to risk ear damage. More publicity should be given to the side-effects and the young especially should have explanations given to them in school so as to be aware of them.