You heard it your whole life growing up.
"Turn that music down!"
Without doubt; if the human ear is exposed over a long period of time to extremely loud noises, hearing loss is inevitable. The question is how much does it take to reach that point?
Adrenaline Radio takes hearing health very seriously and while we love for you to play our programming loud and proud we want everyone to enjoy good hearing health. So we put together this informative guide to hearing and sound levels.
The human ear is divided into three parts: the Outer Ear the Middle Ear and the Inner ear. Sound waves are collected by the visible part of the outer ear, focused through the ear canal where it is filtered to the Cochlea. The cochlea is filled with fluid whose capacity is a fraction of a drop. This is where the pressure from a sound wave is changed into an electrical current that the brain is able to read and process.
Microscopic hair cells (cilia) are attached to nerve fibers that feed the auditory nerve where electrical impulses are passed on to the brain. Each hair cell has may hairs that bend when responding to sound. The cells closest to the edge of the Cochlea respond to high frequencies and those opposite respond to low frequencies.
High sound pressure levels cause the hairs to break or shear off. As the hairs become damaged, hearing impairment increases.
In the image to the left you can see normal sensory cells in Part A compared to severely damaged sensory cells in Part B.
Real World Application
Knowing the science behind hearing is great, but let's look at some real-world applications and scenarios.
When hearing loss occurs, it its typically gradual and without warning over a lifetime, this is not to say that aging causes hearing loss, constant exposure to loud sounds is typically the root cause. Although in certian instances sudden exposure to a loud sound can cause permanent damage.
The Human ear can pick up an extremely wide range of sounds from 0 decibels (db) though 120 db which is considered the "Threshold of Pain." Some common sounds and their everyday db rating are as follows.
10db, Insect noises at night, open field
40db, Subdued conversation
50db, Average office
60db, Average conversation
70db, Busy street
90db, Heavy truck traffic; baby crying; trombone, 16 inches away
96db, Jack hammer
110db, Electric guitar amp at maximum volume, 6 inches away
140db, Inside a bass drum, airport runway
150db, Permanent damage to hearing
160db, Jet engine, close up
180db, Rocket engines
220db, 12 feet in front of a cannon below the muzzle.
As you can see we live at a relatively high volume level in our daily lives, unfortunately there is not much we can do to avoid common noises, the best protection is to prevent ourselves from being exposed to overtly loud sounds. When you are exposed to high levels of sound make sure to have ear protection available, it is critical to pay close attention to how your ears are reacting in any particular situation, if your ears are ringing or if you are experiencing the situation where your ears feel like they are being stuffed with cotton balls, stop what you are doing immediately and seek some form of ear protection.
*Ear-buds and headphones carry an extremely high risk of causing damage because of the close proximity to the ear, always be cautions when using these items.*
The best forms of ear protection are earplugs and industrial headsets, earplugs can be either disposable or custom-fitted to your particular ear. Typically these protective measures can lower sounds 15-20 db. I hope this article helps you to further understand how hearing works and ways to prevent hearing damage, because lets face it nobody wants to be the person who says "What?" every time someone says something.
The following chart is a Occupational Safety and Health Association (OSHA) guide for daily noise levels and exposure.