Glossary of Terms

Audiogram

An audiogram is a graph produced during a hearing evaluation that plots your hearing threshold (the quietest sound you can detect) at multiple frequencies, revealing the degree and pattern of any hearing loss.

Air-Bone Gap

An air-bone gap is the difference between air conduction and bone conduction thresholds on an audiogram, indicating that sound is being blocked before reaching the inner ear.

Auditory Processing Disorder

Auditory processing disorder (APD) is a condition in which hearing sensitivity is normal but the brain has difficulty interpreting and organizing what it hears, particularly speech in noise.

Asymmetric Hearing Loss

Asymmetric hearing loss is a clinically significant difference in hearing thresholds between the two ears, typically 15-20 dBHL or greater at one or more frequencies.

Auditory Nerve

The auditory nerve (cranial nerve VIII) transmits electrical signals from the hair cells of the cochlea to the brainstem and auditory cortex, where they are interpreted as sound.

BPTA (Bayesian Pure Tone Audiometry)

BPTA (Bayesian Pure Tone Audiometry) is an adaptive hearing screening protocol that uses statistical inference to estimate your hearing threshold at each frequency more efficiently than traditional fixed-step methods.

Bone Conduction

Bone conduction is the transmission of sound to the inner ear through vibrations of the skull bones, bypassing the outer and middle ear entirely.

Binaural Hearing

Binaural hearing is the ability to hear with both ears simultaneously, allowing the brain to determine sound location, improve speech understanding in noise, and reduce listening effort.

Conductive Hearing Loss

Conductive hearing loss occurs when sound is blocked or weakened before it reaches the inner ear, typically due to a problem in the outer or middle ear.

Cochlea

The cochlea is the fluid-filled, spiral-shaped structure of the inner ear that converts mechanical sound vibrations into electrical nerve signals the brain interprets as sound.

Cerumen Impaction

Cerumen impaction is the excessive accumulation of earwax (cerumen) in the ear canal to a degree that causes symptoms or prevents examination and testing.

Hearing Threshold

Your hearing threshold is the quietest sound you can detect at a given frequency, measured in decibels hearing level (dB HL). It is the fundamental measurement of any hearing test.

Hearing Threshold Level

Hearing threshold level (dBHL) is the intensity at which a person can just detect a sound 50% of the time, expressed relative to the average threshold of normal-hearing young adults.

Hearing Aid Styles

Hearing aid styles refer to the physical form factor of the device: where the electronics sit, how it connects to the ear, and how visible it is. Common styles include BTE, RIC/RITE, ITE, ITC, and IIC.

Hearing Loop

A hearing loop (audio induction loop) is an assistive listening system that transmits audio magnetically from a venue's sound system directly to telecoil-equipped hearing aids and cochlear implants.

Meniere's Disease

Meniere's disease is a disorder of the inner ear characterized by episodic vertigo, fluctuating sensorineural hearing loss, tinnitus, and a sensation of fullness in the affected ear.

Masking

Masking in audiology is the presentation of a noise to the non-test ear during audiometric testing to prevent it from detecting sounds intended for the test ear, ensuring valid, ear-specific thresholds.

Noise-Induced Hearing Loss (NIHL)

Noise-induced hearing loss (NIHL) is permanent hearing damage caused by exposure to loud sounds that physically destroy the hair cells of the inner ear. It is cumulative, irreversible, and entirely preventable.

OTC Hearing Aids

Over-the-counter (OTC) hearing aids are FDA-regulated hearing devices available without a prescription or audiologist visit, introduced in 2022 for adults with perceived mild to moderate hearing loss.

Otosclerosis

Otosclerosis is a condition of abnormal bone remodeling in the middle ear, typically causing the stapes (the smallest bone in the body) to become fixed, resulting in conductive or mixed hearing loss.

Ototoxic Medications

Ototoxic medications are drugs with the potential to damage cochlear hair cells or the vestibular system, causing hearing loss, tinnitus, or balance problems, sometimes permanently.

Pure-Tone Average (PTA)

A pure-tone average (PTA) is a single number representing your average hearing threshold at the speech frequencies most important for understanding conversation, typically 500 Hz, 1,000 Hz, and 2,000 Hz.

Presbycusis

Presbycusis is the gradual, bilateral hearing loss that occurs as a natural part of aging, primarily affecting high-frequency sounds. It is the most common cause of hearing loss in adults.

Sensorineural Hearing Loss

Sensorineural hearing loss is the most common form of permanent hearing loss, caused by damage to the hair cells of the inner ear (cochlea) or the auditory nerve pathway.

Speech-in-Noise Difficulty

Speech-in-noise difficulty is the inability to understand speech clearly when background noise is present. It is one of the most common and earliest signs that hearing is changing.

Speech Discrimination Score

A speech discrimination score (also called word recognition score) is the percentage of words a person correctly repeats when presented at a comfortable listening level, measuring speech clarity rather than just volume.

Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSNHL) is a rapid loss of 30 dBHL or more across three consecutive audiometric frequencies occurring within 72 hours, most often in one ear. It constitutes a medical emergency.

Tinnitus

Tinnitus is the perception of sound without an external audio source, most commonly ringing, buzzing, or hissing. It affects an estimated 15% of adults in the United States.

Telecoil

A telecoil (T-coil) is a small electromagnetic coil inside many hearing aids and cochlear implants that wirelessly receives audio signals from telephones and hearing loop systems.

Word Recognition Score

Word recognition score is the percentage of spoken words correctly identified at a comfortable volume, reflecting the clarity with which the auditory system processes speech.