Hearing loss is a common problem with a wide variety of causes, such as prolonged exposure to loud noises, as well as aging, injury, disease, infection, ear wax buildup, genetics and medication side effects.

Hearing tests can help pinpoint the source of hearing loss. Hearing aids are medical devices that assist hearing by amplifying sounds.

Hearing Tests

When you hear something, sound waves travel through a series of ear structures called the outer, middle and inner ear, where they are converted into electrical signals. These signals are carried by the auditory nerve to the brain, which translates the signals into recognizable sounds. Together, these structures are known as the body’s auditory system.

Any disruption or damage to the auditory system can result in hearing loss. Hearing tests measure hearing sensitivity across a full range of sounds and find where in the auditory system the problem is occurring. Hearing test results are recorded in a graph called an audiogram, which charts hearing sensitivity at different pitches.

Several tests can be used to diagnose hearing loss and identify the cause.

• Acoustic reflex testing measures how much a tiny muscle in the middle ear tightens in response to loud sounds.
  
• Auditory brainstem response testing, also called auditory-evoked potential testing, evaluates how well the auditory nerves inner ear, called the cochlea, are working.
  
• Bone conduction testing sends sound vibrations directly to the inner ear, bypassing blockage or damage of the outer or middle ear.
  
• Pure tone testing helps determine the quietest sound that can be heard at various pitches. This test includes both ears at the same time.
  
• Otoacoustic emissions testing evaluates how well the cochlea works.
  
• Speech testing evaluates how clearly spoken words can be heard, repeated and understood.
  
• Tympanometry evaluates how well the eardrum moves in response to sounds.

Hearing Aids

Hearing aids are medical devices worn in the ear to assist hearing. A hearing aid is made up of a microphone, amplifier and speaker. The microphone picks up sounds, routes them through the amplifier, which makes sounds louder, and then sends them to the ear through the speaker. Hearing aids can be worn in one or both ears.

Hearing aids may amplify all sounds, or only specific sound frequencies. Some hearing aids can emphasize sounds from a single direction, filter out background noise, or connect directly to a TV, computer or other audio device.

Hearing aids cannot restore normal hearing or slow down hearing loss, but a properly programmed aid will not harm hearing. Most modern hearing aids use digital technology, making them easier to program and adjust for specific hearing situations. It may take several weeks or months to adjust to wearing a hearing aid; most problems can be overcome with the help of an audiologist.

There are several types and styles of hearing aids currently available. The best type depends on the underlying cause and degree of hearing loss.

• Behind-the-ear (BTE) aids contain the microphone and amplifier in a case behind the ear, with a small tube that connects to the speaker inside the ear opening.
• Mini BTE aids are a smaller version of the traditional BTE style that are worn on the ear.
• In-the-ear (ITE) aids contain all parts in a case that fills the entire ear opening.
• In-the-canal (ITC) and completely-in-canal (CIC) aids are custom fitted and nearly hidden in the ear canal.

Cochlear implants may be another option for children and adults who are deaf or severely hard of hearing. These surgically implanted electronic devices mimic the function of damaged inner ear structures, translating sounds into electrical signals that travel to the brain via the auditory nerve.