August 1, 2020
It is no secret loud sounds damage hearing. We warn kids of the dangers of ear bud use. We see the effects in people who have spent years working in factories, serving in the military, playing in bands or using power tools. Noise exposed people are more likely than others to become hard of hearing. Let us explore several questions about noise exposure. Why does this happen? Can it be prevented? Can it be treated?
Hearing is a chain of events in which sound energy is converted into nerve impulses that stimulate the brain. In short, the outer ear collects sound and channels it to the eardrum. The drum vibrates along with three tiny bones behind it. This creates waves in the fluid of the inner ear. When the fluid waves travel, they stimulate cells called “hair cells”, so called because they have hair-like projections (cilia) that waggle in the fluid. This waggling triggers nerve impulses to the brain.
Significantly, there are actually two types of hair cells. The INNER hair cells are the receptors that send the signal on. Next to each one sits a set of OUTER hair cells, which act like tiny amplifiers – biological “hearing aids” we are born with. These are the cells that bear the brunt of the noise damage, particularly in the region that detects high pitched sounds. The inner receptor cells can’t detect soft noises by themselves. Short term damage can resolve within days; long term damage may be permanent. This damage is can progress with time and continued exposure.
Currently there are excellent products and strategies to minimize noise damage. Keep in mind damage is a function of INTENSITY and DURATION. The louder the noise the less time it takes to do damage. Reducing exposure time lessens damage. OSHA workplace regulations take this into account. There are ear plugs, muffs and headsets that reduce sound levels. Limiting volume for music reduces damage. Consider increasing your distance from loud sounds whenever possible.
When noise damages hearing, communication suffers, particularly soft speech in background noise. Modern “open-fit” hearing instruments can fill in the gaps selectively. They also have multiple microphones to emphasize sound in front of the wearer. Many have noise reduction circuits as well. We are able to help. The first step is a thorough evaluation of the ears. As always, we aim to keep you on a clear path to good hearing and ear health.