Hearing Loss

What are the different types of hearing loss?

There are two basic types of hearing loss: sensorineural and conductive. Some people have a combination of the two—known as mixed hearing loss.

Sensorineural hearing loss. More than 80% of people who are hard of hearing have sensorineural hearing loss. This type is caused by damage to the sensory (hair) cells in the ear or to the nerves that transmit sound messages to the brain. Sensory cells can be damaged gradually with aging or ongoing exposure to loud noise. Or they can be destroyed suddenly by loud noises, toxic drugs, or head injuries. Sensorineural hearing loss is usually permanent.

Conductive hearing loss. This type of hearing loss is caused by something that physically blocks or hinders sound waves from passing through the outer or middle ear. The source of the obstruction varies and can include earwax, accumulation of fluid, inflammation from an ear infection, a cyst or other abnormal growth, or a foreign body lodged in the ear.

Other causes of conductive hearing loss include:

• Disorders of the ossicles (the three small bones in the middle ear)
• Unequal air pressure in the middle ear (as can happen during plane flights)
• A birth defect in which the ears haven’t developed properly.

Unlike sensorineural hearing loss, conductive hearing loss usually is treatable with medication or surgery.

How is hearing loss diagnosed?

Diagnosing hearing loss usually begins with an exam by your doctor followed by a referral to hearing loss professional like an otolaryngologist (known as an ear, nose, and throat doctor) or an otologist who specializes in ear problems.

If there is concern for hearing loss, you'll next see an audiologist for a series of auditory tests. These are performed in a soundproof booth where you listen to sounds through each ear separately. The tests evaluate whether you can hear low, mid-range, and high frequencies and how well you can hear and understand spoken words. The results identify your type of hearing loss—conductive, sensorineural, or mixed.

Depending on the test results, other tests may be recommended. For example:

• Tympanometry, an exam to determine if your hearing difficulty stems from the middle ear.
• Imaging tests, like CT scans or MRIs, look for abnormal growths in the ears or brain.

What do hearing aids do?

If your care team determines that you are a candidate for hearing aids, you will be sent for a hearing aid evaluation.  There are many kinds of hearing aids, but they all counter hearing loss by amplifying sounds and filtering out certain types of noise. 

A hearing aid has three essential parts: a microphone, an amplifier, and a speaker. Sound is received through the microphone, which converts the sound waves to electrical signals and sends them to the amplifier. The amplifier then increases the power of the signals and sends them to the ear through a speaker.

A prescription hearing aid is individually fitted and fine-tuned based on the severity of a person’s hearing loss. Individuals may need one hearing aid or two. 

Hearing aids are not the same as personal sound amplification products (PSAPs) sold at most drug stores. PSAPs are not tailored to an individual's hearing loss and aren’t regulated by the FDA or intended to treat hearing loss. Rather, they are an alternative for people who only experience difficulties in specific situations, like listening to the TV. While PSAPs can amplify sound, they can’t be programmed to boost specific sound ranges or mute certain sounds. They simply turn up the volume on all sounds.

Hearing aid options

What type of prescription hearing aid you need depends on several factors, such as the severity of your hearing loss, the style you prefer, and your budget. 

Hearing aids can be costly. The average price for a single hearing aid is about $2,000 but can vary depending on the brand and style. While Medicare doesn’t cover hearing aids, some Medicare Advantage plans do cover some costs. 

A possible cost-saving option is the newly available over-the-counter hearing aids (also not the same as PSAPs). Prices range from $200 to $1,000 each. You can buy them without seeing a doctor or audiologist. However, they are only for people with mild or moderate hearing loss, so it is still necessary to see your physician and audiologist before exploring this option. 

Prescription hearing aids are divided into two categories: in-the-ear and behind-the-ear. In-the-ear hearing aids come in the following styles:

Completely-in-the-canal (CIC). About the size of a jellybean but slimmer, the entire aid fits inside the ear canal. Someone looking directly at your ear from the front can't see the hearing aid, although it may be partially visible from the side.

Invisible-in-the-canal (IIC). An IIC hearing aid is placed deeper into the ear canal, past the second bend. It is entirely invisible from any view of the ear. It is a smaller version of the CIC type with fewer features.

Lyric extended wear. These are smaller than CIC models and placed even deeper than IIC models, just 4 millimeters from the eardrum. They are disposable with a battery life of up to four months. They can be worn while sleeping, showering, and exercising. 

In-the-canal (ITC). Ideal for people who can’t wear smaller models or need a stronger amplification than smaller hearing aids can provide. 

In-the-ear (ITE).  ITE aids fit just outside the ear canal and fill the outer cavity of the ear. They help people with mild to severe hearing loss. The aid also is larger and easier to manipulate than other styles.

Behind-the-ear (BTE) is the oldest and largest style of hearing aid in general use. The receiver, microphone, and other electronic components are housed in a plastic case that hooks behind the ear. A narrow tube carries sound from the case to an earmold custom-made to fit in the ear’s opening. While appropriate for all types of hearing loss, BTEs are best for people with severe to profound hearing loss.

Receiver-in-the-canal BTE. Compared to a regular BTE, the receiver sits inside an earbud worn in the ear canal. A wire insulated in a thin tube connects the receiver to the BTE case behind the ear. Receiver-in-the-canal aids help people with mild to severe hearing loss.

Surgery to treat hearing loss

Although hearing aids can help most people with hearing loss, some people may benefit from surgery. The following are the most common types of surgical procedures.

Bone-conducting aid. This is intended for people who can’t wear regular hearing aids because they have chronic ear infections or do not have an ear canal. It is also used in people with single-sided hearing loss. The aid reroutes sound vibrations directly through your skull to your inner ear. A metal screw is surgically implanted into the skull behind the ear. Then the screw is connected to an external hearing aid.

Cochlear implant. Cochlear implants are used for adults and children with severe to profound sensorineural hearing loss in both ears in which a hearing aid has little or no effect. The doctor surgically implants an electrical device and later attaches external parts, including a microphone and speech processor, to restore some hearing. .

Several additional types of surgery are available to help correct other kinds of hearing loss. For example:

Stapedectomy. This operation corrects otosclerosis, a common cause of conductive hearing loss characterized by abnormal growth around the stapes bone (in the middle ear) or the otic capsule (the bone surrounding the inner ear's labyrinth). Working through the ear canal, the surgeon removes all or part of the stapes and replaces it with an artificial one.

Tympanoplasty. This surgery patches holes in an eardrum that have not healed after being ruptured by trauma or infection.

Mastoidectomy.  This surgery is often included with a tympanoplasty and is performed for patients who have chronic infections or build of skin debris in the ear called, cholesteatoma.

Myringotomy. This outpatient procedure is performed mainly on children with persistent fluid buildup in the middle ear because of recurring ear infections that don’t respond well to antibiotics. A ventilation tube is inserted into the eardrum to drain fluid from the middle ear. The tubes are left in place for six to 18 months.