AUDIO MYTHS 2

Loud noise doesn't damage your hearing......

We recently heard a DJ say he had read an article saying that muscles in the ear strengthen with exposure to loud sounds, and thus the ear doesn’t get damaged.


I discussed this with a friend of mine, a professional musician who has trained as an audiologist, and he concluded that this was referring to the reflex muscle that tensions the eardrum when loud noises hit it. “The eardrum has a certain amount of flexibility which allows it to detect sounds over a huge pressure range (over 1,000,000 times from softest to loudest), but when a very loud sound occurs at the eardrum, this little muscle tightens up and pulls the eardrum tight to prevent tearing or perforations. However, just like any other muscle, it can only stay tensed for a short while before fatigue sets in and it starts to relax, and then there is no protection. This tightening only protects the eardrum, and the ossicles (the little bones called the hammer, anvil and stirrup that translate a large movement at the eardrum to a very small movement at the cochlea) from excessive movement, which in turn stops the transmission of overly large inputs to the cochlea, thus affording a degree of protection to the inner ear. However, this only protects via the air conduction route, and you are still at risk from the bone conduction route (sound so loud, that it penetrates your skull and goes straight into the cochlea). When you are exposed to high sound pressure levels, air transmission via the eardrum and bone conduction will both cause sensorineural hearing loss (damage to the little hair cells in the cochlea). This is the cause of the ringing that you get in your ears after prolonged exposure. Sensorineural hearing loss is irreversible and should be avoided at all cost by the use of suitable hearing protection and where you can, limited exposure.”



The damage caused by excessive exposure is cumulative. If your ears are ringing after a night’s work or a night out, the chances are you are permanently damaging your hearing. The damage may not be immediately obvious or measurable, but you will slowly notice that you can no longer hear very quiet sounds, and that gradually speech becomes more difficult to understand.



All professionals working with loud sound should have their ears tested regularly and wear earplugs, preferably moulded ones with a flat frequency response. This costs money, but preserving the tools of your trade is what will enable you to continue working effectively.



It is of great concern to many that there will be a generation with self-inflicted deafness. Last month’s myth didn’t pose any threat to anyone’s well being; misunderstandings like this one will.



With special thanks to Mike Watson.