Hearing Loss

Basic Facts

What is Hearing Loss?

About a third of adults older than 65—and half of those older than 85—have some kind of hearing problem. Hearing loss is the third most common chronic disease among older adults. 

Hearing loss is more than an inconvenience. It can lead to depression, withdrawal, anger, loss of self-esteem, and overall unhappiness with life. There is even some evidence it can affect your memory and other cognitive processes, as well your mobility. Because it can make communicating with your healthcare providers difficult, hearing loss can even jeopardize your overall health.

Age-related hearing loss is also known as presbycusis. It happens gradually over time. While those around you may notice problems, you may think you are fine. Age-related hearing loss has no known cure, and while technologies such as hearing aids, cochlear implants, and assistive devices improve hearing, they do not restore hearing to normal.

The bottom line is that treating hearing loss can significantly improve the quality of your life and interactions with others, including relieving the depression often associated with hearing loss.

Sound and the Ear

Sound is defined in two ways:

  1. Frequency (pitch) is measured in cycles per second (Hz). Normal speech falls in a frequency range of 250 to 8,000 Hz. Most of the range important for understanding speech lies in the higher frequencies (for example, 1500 to 4000 Hz).
  2. Intensity (loudness) is measured in decibels. The lowest intensity at which a sound must be generated to be heard is called the threshold for hearing. The higher your individual threshold, the louder the sound must be for you to hear, and the worse your hearing is.

 

Normal hearing depends on three components:

  1. The ear
  2. The nerves leading from the ear to the brain
  3. The brain

 

The ear modifies the sounds coming from the outside. The brain processes and helps us understand and interpret sound.

Hearing starts with a sound wave, or vibration. The sound wave travels through the outer part of your ear (ear canal) and travels to the eardrum. The eardrum is a thin membrane that separates the outer parts of the ear from the inner parts.  When the eardrum vibrates, three bones (the auditory ossicles) send the vibration to the cochlea (a tiny spiral cavity with sensory cells).  Then, the signals are carried by nerve fibers to the brain, where understanding speech takes place.

Definition of Hearing Loss 

Hearing loss is defined as the loss of the ability to hear pure tones across the range of auditory frequencies required to understand speech.  Hearing loss is a major reason for difficulties in understanding what others say, especially in noisy conditions. 

There are three main types of hearing loss:

  1. Conductive
  2. Sensorineural
  3. Mixed

 

Age-related hearing loss is sensorineural in nature.  See Causes and Symptoms for descriptions of each type.

 

Last Updated June 2020