Research from the University of Leicester in the UK has found that noise induced hearing loss is primarily caused by a thinning of the myelin coat that protects the auditory nerve cells in the inner ear. This finding takes researchers one step closer to developing preventive strategies and maybe even cures.
It is well known in research that noise induced hearing loss slows down the auditory signals, which makes it difficult to understand speech. Until recently however, the mechanisms behind this have been unclear.
Two possible causes
Earlier studies have shown that loud noises can narrow the protective myelin coat of the auditory nerves in the inner ear, while other studies have found that loud noises make the gaps, also known as nodes of Ranvier, between the myelin coats longer. These facts made the researchers question which one of the two was causing the actual noise induced hearing loss.
The researchers simulated the two possible causes by using computational modeling. From the simulation, it was possible to conclude how the two factors affected auditory signaling. The findings show that the thinning of the myelin coat is the primary cause for noise induced hearing loss, while lengthening of the nodes of Ranvier only has a small effect on the hearing loss.
The researchers now plan to focus on testing medicines to generate myelin repair.