Researchers at the United Kingdom's University of Leicester have found that turning your music up too loud can damage the coatings of nerve cells in your ears.
Research has shown, and your mother has said, that listening to music too loudly can cause temporary hearing loss, and even tinnitus, or ringing in the ears. But this research indicates the reasons behind that occurrence and the underlying cellular reasons.
Noises higher than 110 decibels can cause temporary hearing loss and tinnitus, or the ringing in your ears after going to a concert. Noises at that level are comparable to the noise emitted by jet engines. In fact, the highest setting on an mp3 player is 110 decibels so, while it is unlikely that you are listening to music at that level (you definitely shouldn't be!), it is not uncommon for people to turn their music all the way up in a busy environment like the train or a mall.
Nerve cells carry electrical signals from the ears to the brain, and are covered with a coating called the myelin sheath. Just like the myelin sheath is damaged during inflammation from multiple sclerosis, so too is it damaged when the ear is exposed to sounds that are too loud. That damage means that the nerves can no longer properly relay auditory signals to the brain.
But, interestingly, that damage can be reformed. That means that hearing loss can be temporary, and full hearing ability can return.
Dr. Hamann said in a statement, "We now understand why hearing loss can be reversible in certain cases. We showed that the sheath around the auditory nerve is lost in about half of the cells we looked at, a bit like stripping the electrical cable linking an amplifier to the loudspeaker. The effect is reversible and after three months, hearing has recovered and so has the sheath around the auditory nerve."