Acoustic neuroma
A slow-growing, benign tumor on the auditory and vestibular nerves that develops when cells that cover and insulate the nerves overproduce.

Acute otitis media
An infection of the middle ear that often includes pain, fever and conductive hearing loss.

Aplasia
Malformation of the inner ear.

Asymmetrical hearing loss
The degree and/or configuration of the loss is different for each ear.

Audiogram
The graphic representation of the results of a hearing test to measure how well sounds at various frequencies are heard. It may also record results of other tests that indicate how well various parts of your ear (outer ear, middle ear, and inner ear) are working.

Audiologist
A health-care professional with a Doctor of Audiology (Au.D.) or a Master's degree in audiology and licensed by one of the audiology associations. Audiologists are trained to identify, measure, and evaluate hearing loss and related disorders and to provide non-medical management of hearing loss, including hearing aids, assistive devices and rehabilitation.

Auditory Brainstem Implant (ABI)
A device similar to a cochlear implant, except the electrodes are implanted directly in the base of the brain.

Auditory Deprivation
Absence or restriction of auditory stimuli to which the individual responds.

Auditory Nerve
A bundle of nerve fibers running from the cochlea to the brain.

Auditory System
The anatomical system that transfers energy from sound waves to neural activity for processing by the auditory centres in the brain. The auditory system consists of the outer ear, the middle ear, the inner ear, and the central auditory pathways

Bass
Sound produced in the low pitch range.

Bilateral Hearing Loss
Bilateral hearing loss means both ears are affected.

Cochlea
Coiled, snail-like tube in the temporal bone containing the auditory elements of the inner ear. The cochlea converts incoming sound waves from the middle ear into electrical signals and transmits these signals to the auditory nerve.

Cochlear Implant
A device that substitutes for damaged (dead) hair cells of the inner ear. It consists of an electrode array that is surgically implanted in the cochlea. It delivers electrical signals to the auditory nerve from an external processor, enabling people with severe-to-profound hearing loss to perceive sound again. Cochlear implants are an option if hearing aids do not give you significant benefit.

Conductive Hearing Loss
Hearing loss due to abnormal conditions that block the passage of sound through the outer and/or middle ear, such as a ruptured ear drum or fluid (infection) in the middle ear (otitis media). It usually involves a reduction in the ability to hear faint sounds and can often be medically or surgically corrected.

Configuration of Hearing Loss
The extent of hearing loss at each frequency and the overall picture of hearing that is created. A hearing loss that only affects the high frequencies would show good hearing in the low frequencies and poor hearing in the high frequencies. If only the low frequencies are affected, the configuration would show poorer hearing for low tones and better hearing for high tones. Some hearing loss configurations are flat, indicating the same amount of hearing loss for low and high tones.

Deaf / deaf
When capitalized, Deafness refers to those who consider themselves a part of the Deaf culture, and choose to communicate using a signed language such as American Sign Language (ASL), instead of spoken communication. When not capitalized, the definition is for a person with little or no measurable hearing, i.e. 90+ dB hearing loss. A person with severe or profound hearing loss.

Decibel (dB)
The unit that measures the intensity (loudness) of sound. People with very sensitive hearing can hear sounds softer then 0 dB (expressed in negative numbers). The dB levels of some common sounds are:

• Normal breathing 10 dB
• Whisper 20 dB
• Normal Conversation 60 dB
• Vacuum Cleaner/Hair Dryer 70 dB
• City traffic 80 dB
• Lawn Mower 90 dB
• Chain Saw 110 dB
• Rock Concert 110 dB
• Snowmobile 120 dB
• Firecrackers 140 dB

Degree of Hearing Loss
The severity of the loss. The numbers are representative of the patient's thresholds, or the softest intensity at which sound is perceived.

Dynamic Range
The range of loudness between the softest sound that a person can hear and the loudest sound they can stand.

Ear
Organ related to hearing and equilibrium. Contains three main parts: outer, middle, inner.

Ear Canal
The inch-long pathway leading from the outer ear to the eardrum (also called the Tympanic Membrane).

Ear Infection
The presence and growth of bacteria or viruses in the ear.

Ear, Nose and Throat Physician
See "Otolaryngologist".

Eardrum
Receives and transmits sound waves.

Eustachian Tube
The small tube connecting the back of the throat to the middle ear which neutralizes air pressure on both sides of the eardrum. A sore or swollen throat can close this tube, causing ear pain.

Frequency
The number of vibrations per cycle/second in a sound wave. Typically referred to as a Hertz (Hz).

Hard of Hearing
People who have varying amounts of hearing loss but usually not enough to be considered deaf. Their losses can range from slight to severe. Hard of hearing people understand some speech with or without hearing aids.

Hearing Aid
A device that amplifies sound and directs it into the ear canal. A hearing aid usually consists of a microphone, amplifier and receiver. Some digital hearing aids attempt to reduce background noise.

Hearing Loss
The loss of hearing ability characterized by decreased sensitivity to sound in comparison to normal hearing. One commonly used classification defines loss as follows:

• Normal hearing: -10 to 15 dB
• Slight loss: 16 to 25 dB
• Mild loss: 26 to 40 dB
• Moderate loss: 41 to 55 dB
• Moderately severe loss: 56 to 70 dB
• Severe loss: 71 to 90 dB
• Profound loss: 91 to 120 dB

Inner Ear
Portion of the ear located in the temporal bone. Includes vestibule, semicircular canals and cochlea.

Middle Ear
The portion of the ear that extends from the eardrum to the cochlea. It contains the three smalles bones in your body (commonly known as the hammer, anvil, and stirrup), whose job it is to carry and amplify the vibrations of the eardrum to the cochlea.

Mixed Hearing Loss
When a conductive hearing loss occurs in combination with a sensorineural hearing loss.

Neurologist
See "Otologist".

Otolaryngologist (M.D. or D.O.)
Licensed physicians who specialize in diseases of the ear, nose, and throat (ENT).

Otologist (M.D. or D.O.) and Neurologist (M.D. or D.O.)
Highly specialized Otolaryngologists knowledgeable in the basic sciences of hearing, balance, nerve function, infectious disease, and anatomy of the head and neck.

Otosclerosis
The abnormal growth of bone of the middle ear. This bone prevents structures within the ear from working properly and causes hearing loss. Treatable with surgery.

Ototoxic
A chemical or drug that can temporarily or permanently damage your hearing. Ototoxic medications may aggravate an existing hearing problem or cause new problems. Most common examples are certain antibiotics, loop diuretics, and chemotherapeutic agents.

Outer Ear
The visible part of the ear (pinna) and ear canal.

Pinna
Portion of the outer ear primarily made of cartilage.

Pitch
Intensity of sound as it relates to frequency. Can range from low to high.

Presbycusis
Age-related hearing loss.

Sensorineural Hearing Loss
Hearing loss that occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain. Sensorineural hearing loss cannot be medically or surgically corrected. It is a permanent loss.

Symmetrical Hearing Loss
The degree and configuration of hearing loss are the same in each ear.

Tinnitus
The ringing of the ear caused by disturbance in auditory nerves or brain dysfunction.

Treble
Highest part of the harmonic voice.

Unilateral Hearing Loss
When hearing is normal in one hear but there is hearing loss in the other ear.

Volume
Degree of loudness and/or intensity