Hearing Loss: Turn down the volume!
Every day we go about our business, not realizing how often our ears are bombarded with sounds. It is easy to take for granted the things we hear - the voices of loved ones, our favorite music, and the everyday noises of life. But exposure to repeated noise, especially at loud levels, can damage the most sensitive parts of our inner ears. This can lead to permanent hearing problems, without us even being aware that it’s happening. Noise-induced hearing loss is 100% preventable. However, once acquired, it is permanent and irreversible.
The ear consists of three parts: the outer ear, the middle ear, and the inner ear. Each part works together to convert sound waves into nerve impulses that travel to the brain, where they are perceived as sound.
· The Outer Ear includes the part of the ear we are able to see (auricle) and the ear canal (auditory canal) – the tunnel that ends at the ear drum. The outer ear is shaped to capture sound waves and funnel them through the ear canal to the eardrum (tympanic membrane), a thin membrane that separates the outer ear from the middle ear
· The Middle Ear consists of the eardrum, a small air-filled chamber containing three tiny bones that connect the eardrum to the inner ear (malleus, incus, stapes), and the auditory tube (eustachian tube) - a tube that connects the middle ear to the airway in the back of the nose. (The bones in our middle ear are the smallest bones in our body!)
· The Inner Ear is a complex structure consisting of the cochlea, which is the organ of hearing, and the semicircular ducts, which is the organ of balance. The cochlea, a hollow tube coiled in the shape of a snail's shell, is filled with fluid. It contains 20,000 specialized hair cells called cilia
How we hear:
1. Sound waves enter the outer ear, travel through the ear canal, and hit the ear drum (outer ear).
2. The eardrum vibrates from the incoming sound waves and sends these vibrations to the three tiny bones in the middle ear.
3. These bones increase the sound vibrations and send them to the cochlea (inner ear).
4. The sound vibrations cause the fluid inside the cochlea to ripple, forming a wave. Cilia (hair cells) ride the wave.
5. As the cilia move up and down, channels open up causing a chemical reaction. This creates an electrical signal.
6. The auditory (hearing) nerve carries this electrical signal to the brain, which turns it into a sound that we recognize and understand.
When cilia are damaged and then destroyed by too much noise, they don’t grow back. So hearing is permanently harmed.
After leaving a very loud event, such as a concert or football game, you might notice that you don’t hear as well as before. You may not hear whispers, sounds might seem muffled, or you may hear ringing in your ears. This is because the hair cells (cilia), similar to blades of grass, will bend more if the sound is louder, but they will become straight again after a recovery period. Normal hearing usually returns within a few hours to a few days.
Long-term exposure to noise causes most noise-induced hearing loss. Noise above 85 dB (decibels) over a prolonged period of time may start to damage your hearing. Loud noise above 120 dB can cause immediate harm to your ears. The louder the sound, the shorter the amount of time it takes for hearing loss to occur:
· 0 dB: Faintest sound heard by human ear
· 30 dB: Whisper, quiet library
· 60 dB: Normal conversation, sewing machine, or background music
· 90 dB: Lawnmower, shop tools, or truck traffic (Hearing loss possible after 2 hours of exposure)
· 100 dB: Chainsaw, pneumatic drill, or snowmobile (Hearing loss possible after 15 minutes of exposure)
· 115 dB: Sandblasting, loud rock concert, or automobile horn (Hearing loss possible in less than 5 minutes)
· 140 dB: Gun muzzle blast, jet engine, or fire crackers (pain and ear injury)
· 180 dB: Rocket launching pad (pain and ear injury)
Hearing loss in teenagers and young adults is especially concerning. According to The American Academy of Pediatricians, kids expose themselves to noise through electronic media that is often louder than what is allowed by law in a workplace. It is estimated that 1 in 6 adolescents has hearing loss caused by exposure to loud noises, such as music played through headphones or ear buds.
How to prevent hearing loss:
· Wear ear protection for anything more than very brief exposure to sound levels above 85 dB
· Turn the volume down
· Walk away from the loud noise
· Take breaks from the noise
· Avoid loud, noisy activities and places
· The personal digital audio player should be set at approximately 60% of maximum (maximum volume is about 100-110 dB; hearing damage can occur after 15 minutes)
· Kids should take breaks after an hour of listening on their audio players. They should be able to hear conversations going on around them while listening to the music
If you suspect or know you have hearing loss, speak with your provider about testing. There are many types of hearing devices that can help you make the most out of the hearing you have. And always take steps to prevent your hearing loss from worsening.