Why Aging May Cause Hearing Loss

As we age, many body parts begin to simply wear out. Age related hearing loss is known as presbycusis and is caused by slow, progressive changes to the nerves and cells of the inner ear. It may be mild or severe but is considered permanent. According to the Center for Hearing and Communication, 12% of the U.S. population (38 million people) experience significant hearing loss and 30-40% of people over 65 experience some type of hearing loss.

Hearing is a complex function. Sounds are generated in the air and “caught” by the “pinna” which is the outer part of the ear. The sound waves are then channeled down the ear canal to the ear drum or tympanic membrane which vibrates and causes the tiny bones to move. This movement pushes the fluid in your cochlea (a spiral shell shaped chamber) and causes the cilia or small hairs in the cochlea to move in a rhythmic fashion. All of this movement is then interpreted by the nerves as sound.

As we age, the bones and movable parts of the inner ear may begin to stiffen, the cilia may be damaged or destroyed, and the nerves may become less sensitive.

Age-related hearing loss usually occurs slowly and progressively over time. Early symptoms usually include:

• Feeling like others are mumbling
• Feeling like others are talking too fast
• Failing to hear sounds behind you
• Environmental noises seem very loud, making it hard to concentrate
• Needing to turn up the television or radio
• Difficulty hearing children or people with high pitched voices

Hearing loss can occur earlier than normal due to:

• Genetics – those with a family history of hearing loss are more likely to experience it themselves
• Loud noises – repeated exposure to loud noises from job conditions or hobbies may damage the cilia of the middle ear and hasten the development of hearing loss
• Smoking – smoking may damage the nerves and cilia of the middle and inner ear
• Medical conditions – diabetes, high blood pressure and certain other medical disorders may increase the risk of hearing loss
• Medications – some drugs are “ototoxic” and cause temporary or permanent damage to the inner ear structure (1)

Early signs of hearing loss can be very frustrating and embarrassing. You may be tempted to hide the fact that you aren’t hearing well by blaming others or your environment. It may make you angry that you feel like others are not speaking clearly or are talking too fast. In many cases, your family will notice that you cannot hear well before you do.(2)

Diagnosis of and Treatment for Hearing Loss

The first evaluation for hearing loss will involve a simple screening test in which your doctor may ask you to cover an ear while he speaks. He may also use a “Tuning Fork” test in which he strikes a two-pronged metal instrument that can produce different sounds and tell whether you can hear in different locations around your ear. The final test may be an “Audiometer” which is a thorough test conducted by an audiologist or hearing professional. Headphones will allow sounds of different pitch and noise levels to be transmitted to one ear or the other. The audiologist may also present words to test your ability to discern certain types of sound.

Most hearing loss is permanent unless it is caused by blockage which can be removed (such as ear wax). Depending on how severe your hearing loss is, you may be advised to get a hearing aid. There are a variety of hearing aids that are available depending upon the severity. In some cases, a simple amplification device may suffice but in other cases, a more complex hearing aid may be needed.

In severe cases, particularly in younger patients, a cochlear implant will help restore hearing. A cochlear implant involves a surgical procedure to insert a portion of a device to compensate for nonworking or damaged parts of the inner ear.(3)

Sources
(1) Facts About Hearing Loss: http://www.chchearing.org/about-hearing-loss/facts-about-hearing
(2) Medline Plus: Age-related hearing loss: http://www.nlm.nih.gov/medlineplus/ency/article/001045.htm (11/19/2012)
(3) Hearing Loss Association of America: Symptoms of Hearing Loss: http://www.hearingloss.org/content/symptoms-hearing-loss (2014)
(4) Mayo Clinic, Diseases and Conditions: Hearing Loss: http://www.nlm.nih.gov/medlineplus/ency/article/001045.htm (8/23/2011)

Author:
Alan S. Berger, M.D.