How We Hear
Because hearing is one of the five senses, the ability to hear is critical for experiencing the world around us. Hearing is a complex process of detecting sound and attaching meaning to it. The human ear responds to different intensity of sounds and can hear a wide range of pitches, ranging from 20HZ to 20,000HZ.
The ear is divided into three parts – the outer ear, the middle ear, and the inner ear.
- The outer ear consists of the pinna, the ear canal, and the eardrum. Sound waves enter the pinna and travel down the ear canal, striking the eardrum and causing it to vibrate.
- The middle ear is a space behind the eardrum that contains three small bones, called ossicles. They are the malleus, incus, and stapes. This chain of tiny bones is connected to the eardrum at one end and to an opening to the inner ear at the other end. Vibrations from the eardrum causes the ossicles to vibrate, which in turn, creates movement of the fluid in the inner ear.
- Movement of the fluid in the inner ear, or cochlea, causes movements of tiny hair cells in the cochlea that convert sound waves into electrical impulses, which are sent from the inner ear up the auditory nerve to the brain to process the sound and interpret its meaning.
*Adapted from American Speech Language and Hearing Association (ASHA)
Hearing loss can affect a person’s ability to detect, hear, or process sounds. There are varying degrees of hearing loss and different types of hearing loss. The type of hearing loss depends on which part of the ear is affected. The most common types of hearing loss include:
CONDUCTIVE HEARING LOSS (CHL)
occurs when there is a problem conducting sound through the outer or middle ear, and it can be temporary or permanent. Some types of conductive hearing loss can be treated medically or surgically. Common causes include ear infections, wax build-up, perforation of the eardrum, swimmer’s ear, atresia, cholesteatoma, and otosclerosis.
SENSORINEURAL HEARING LOSS (SNHL)
occurs when there is damage to the inner ear or to the auditory nerve, and it is usually permanent. Common causes of sensorineural hearing loss include congenital hearing loss, genetic or hereditary hearing loss, hearing loss due to aging, head trauma, exposure to loud noise, illness, or ototoxic medications. The treatment for sensorineural hearing loss usually includes hearing aids or a cochlear implant.
MIXED HEARING LOSS (MXHL)
occurs when there is combination of a conductive hearing loss and a sensorineural hearing loss. In the care of mixed hearing loss, there is damage in both the outer or middle ear and in the inner ear.
Signs of Hearing Loss
- Muffling of speech and other sounds
- Difficulty understanding words, especially against background noise or in a crowd
- Trouble hearing consonants
- Frequently asking others to speak more slowly, clearly and loudly
- Needing to turn up the volume of the television or radio
- Withdrawal from conversations
- Avoidance of some social settings
Common Causes of Hearing Loss
- Excessive loud noise exposure
- Ear infections, trauma, or ear disease
- Certain illness – diabetes, heart or kidney diseases
- Ototoxicity of certain medications
- Presbycusis – deteriorating hearing due to the normal aging process
To assess your hearing, take the Hearing Health Quick Test.
Noise-Induced Hearing Loss (NIHL)
Permanent damage to hearing can be caused by continuous exposure to loud sounds over an extended period of time or by a one-time exposure to an intense sound, such as an explosion. It is important to know that any noise at or above 85 decibels is harmful, and you should take steps to protect your hearing. Prolonged exposure to sound at or above 85 decibels can lead to noise-induced hearing loss.
So what are some warning signs that sounds may be dangerously loud?
- The noise is painful to your ears
- Tinnitus or ringing in your ears after exposure to the noise
- You must shout over background noise to be heard
- After exposure to the noise, you have decreased hearing for several hours
How to Protect Your Hearing
Noise-induced Hearing Loss is usually preventable, take these actions to protect your hearing
- When around sound that is at or above 85 decibels for extended period of time, wear hearing protection such as ear plugs
- Avoid hazardous sound environments
- Maintain a healthy lifestyle
- Turn down the volume when listening through earbuds or headphones
- Have a hearing test if you notice sudden change in your hearing
Hearing Health and Work
Good hearing can help you succeed at work. Statistics show that more than 20 million Americans with hearing loss are in the workforce. Seeking treatment for your hearing loss can improve your work performance and help you stay active physically, socially and cognitively. Working people who use hearing aids show improvement in job performance, professional and interpersonal relationships, and better quality of life.
For our working patients, we offer the latest in hearing aid technology which will allow you to continue to work productively while hearing your colleagues, employees, or customers comfortably.