Hearing Loss Overview

Hearing loss is extremely common, affecting about 48 million Americans today.

About half of all people 75 and older are living with hearing loss. While hearing loss is most common amongst older individuals, it is not only caused by aging, and it can affect us at any age. In fact, the CDC estimates that about 15% of adults aged 18 or over experience some degree of hearing loss. If you think you may be experiencing signs of hearing loss, you are certainly not alone.

Understanding Healthy Hearing

Our auditory system is arguably one of the most complex systems in our bodies. The entire process is extremely complicated, happens in milliseconds, and continues working around the clock. This is why most of us wake up to auditory sounds rather than any of our other senses, because our ears are always on. In order to fully understand hearing loss, it is important to first know how healthy hearing works.

In order to hear each individual sound in our environment, the following process must occur:

  • Sound is collected by the outer ear and travels through the ear canal and towards the eardrum.

  • These sound waves cause the ear drum as well as three tiny bones located in our middle ear to vibrate and move.

  • These vibrations then cause a special liquid located in our spiral-shaped inner ear cochlea to also vibrate and ripple.

  • Tiny and delicate hair-like cells that are located on top of this liquid then also begin to bend and sway with the movement of the liquid.

  • When the tiny hair cells are moved in this manner, it causes then to transmit the vibrations into electric signals for the brain to later process.

  • These electric signals are then sent through the auditory nerve to the brain.

  • It is only at this point that the brain is able to process these electric signals into sounds that we recognize and understand.

 

Types of Hearing Loss

There are four main type of hearing losses: sensorineural, conductive, mixed, and auditory processing.
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Causes of Sensorineural Hearing Loss

Because sensorineural hearing loss is the most common types, we will discuss its causes here. Sensorineural hearing loss is most often caused by one of two factors: excess exposure to noise or natural aging.

woman with hand on ear listening

Noise Induced Hearing Loss

Noise Induced Hearing Loss (NIHL) happens when an individual has been exposed to loud noises. Loud noises can severely damage or delicate hair cells in our inner ears. Most of the time, this involves the exposure to noise over a prolonged period of time - typically a matter of years or even decades. NIHL can happen anywhere we expose ourselves to noises, from our personal listening devices to our leisure activities or workplaces.
inner ear diagram

Natural Aging

The technical term for hearing loss caused by natural aging is called presbycusis. As we grow older, our little delicate hair cells begin to naturally decay, which causes our hearing to become impaired.