Audiometry

Audiometry is the measurement of hearing ability through standardized tests that determine the quietest sounds a person can hear at different frequencies. The results characterize hearing thresholds and help diagnose hearing loss and related disorders.

The core procedure is pure-tone audiometry, which assesses air conduction and bone conduction thresholds using headphones or a bone vibrator. Frequencies typically range from 125 Hz to 8 kHz. Speech audiometry complements this by evaluating speech understanding, with measures such as the speech reception threshold and word recognition score.

Additional tests include tympanometry and acoustic reflex thresholds to evaluate middle-ear function. Objective measures, including otoacoustic emissions and auditory brainstem response, are used when behavioral responses are unreliable or when estimation of auditory nerve function is needed.

A typical interpretation describes hearing thresholds in decibels hearing level (dB HL). Normal hearing usually falls between 0 and 20 dB HL. Thresholds above that indicate conductive, sensorineural, or mixed hearing loss, with patterns guiding diagnosis and management.

Applications include clinical assessment of hearing loss, screening in schools and workplaces, monitoring exposure to ototoxic drugs, and preoperative evaluation. Pediatric audiometry often uses modified procedures such as conditioned play or visual reinforcement to obtain reliable responses.

The test relies on calibrated equipment in a sound-treated environment, and results should be interpreted by qualified clinicians within the context of patient history and examination.