Definition and Overview

Hearing aid is a small device prescribed to patients with hearing problems to improve their ability to listen and communicate. As there is no one-size-fits-all when it comes to these devices, they are customized based on nature of the hearing loss and the shape of the patient’s ear canal.

According to the Hearing Loss Association of America, it’s estimated that at least 48 million people have hearing loss, the degree of which can be mild to severe or profound.

Hearing occurs when sound penetrates the outer part of the ear and travels through the inner ear, which is composed of the cochlea, semicircular canals, and several hair cells. As the sound reaches the middle air, it is “thrown” toward the cochlea, a bony structure that looked like a snail and filled with two types of fluid. The fluids move as the sound hits the cochlea, which in turns stimulates the hair cells. Depending on the pitch, only certain hair cells are activated. Regardless, the stimulation is converted into nerve impulses that can be interpreted by the brain, so the person can distinguish and identify sounds.

A hearing aid works by amplifying the sound that goes through the ears. It is composed of a microphone, which picks up the sound waves and converts them into electronic signals; an amplifier that boosts the signal; and a speaker that allows the person to hear the sound.

There are many different types of hearing aids. These include BTE (behind the ear), RITE (receiver in the ear), ITE (in the ear), ITC (in the canal), and CIC (completely in the canal). The choice depends on a number of factors including the nature of the hearing loss and the shape of the ear canal.

Who Should Undergo and Expected Results

It’s important that a person is able to differentiate between a hearing loss and other ear problems. Not all types of hearing loss would need an aid, especially if the actual cause is an underlying condition. This is because once the cause is treated or managed, more often than not, the problem with hearing also disappears.

Nevertheless, there are people who definitely have hearing loss, a condition that is often permanent. Some of the common causes of are:

  • Congenital – Hearing loss can begin at birth. For this reason, hearing screening is conducted by the pediatrician beginning a few weeks after birth.

  • Environmental – Being exposed to noises, particularly in the long term, can be detrimental to hearing. In fact, there’s a condition known as noise-induced hearing loss that affects about 25 million of people in the United States alone. According to a report by the Centers for Disease Control and Prevention (CDC), hearing loss due to noise can manifest as early as 16 years old.

  • Trauma – A traumatic experience like a serious injury to the ear can lead to permanent hearing loss.

  • Damage to the ears – Damage to the inner ears, even if its’ not trauma related, can still lead to hearing loss. For example, a conductive hearing loss occurs when there’s a problem in the eardrums and ear canal. This may be due to a blockage, which prevents these sections of the ear from passing the same level of sound to the inner ear. Meanwhile, hearing loss is called sensorineural if there’s a problem with the auditory nerves or the cochlea due to aging or infection.

Hearing aids are meant to improve a person’s ability to hear and, in the process, boost communication skills. However, they cannot restore hearing loss. This simply means that if a person removes the hearing aid, he may still not be able to hear clearly. It also cannot stop any future deterioration of hearing.

How Does the Procedure Work?

The first step to fitting a hearing aid is to determine whether the patient indeed has a hearing loss problem and whether he requires or is eligible for a hearing aid. At this point, the patient may have to work with two different healthcare providers: otolaryngologist and audiologist.

An otolaryngologist is a board-certified and licensed medical practitioner who specializes in ears, nose, and throat (ENT specialist). Therefore, he is the only one who can officially diagnose a hearing problem. However, to diagnose it properly, he needs a series of tests, which can be performed by the audiologist. These exams include AOAE (automated otoacoustic emissions), wherein an earpiece connected to a computer is used to deliver clicking sounds while the computer measures the ear’s response, and bone conduction, which is used to assess the performance of the auditory nerves.

If the results point to a hearing loss problem, the otolaryngologist then determines whether the patient requires a hearing aid. If he does, he is referred to the audiologist who then performs more tests including learning the softest and the loudest sound the ears can handle. This can be helpful in choosing the right type of hearing aid. The aid itself may also be adjusted based on the needs of the patient.

The audiologist then discusses all information the patient may need to make a decision. These include features of the hearing aid, their limitations, cost, hearing loss problem, and results of the exams. Once the patient has made a choice, the audiologist then obtains a mold of the ears, which will be sent to the lab for manufacturing.

Once the hearing aid is completed, the patient returns to the clinic where the new hearing aid is fitted and tested to make sure it is set in the correct amplification. The audiologist will also teach the patient how to wear, remove, and take care of the hearing aid. He will then conduct practice sessions to start acquainting the patient with the device.

Possible Risks and Complications

It’s essential that the hearing aid is customized to the needs of the patient, but it doesn’t happen all the time. This means that the fitting of the device may not yield the desired results. The patient then goes through another round of tests, adjustments, and waiting, which can be frustrating for anyone who’s looking forward to hearing properly.


  • Dugan MB. Living with Hearing Loss. Washington DC: Gallaudet University Press; 2003.
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