Audiometrie

Audiometrie, or audiometry, is the scientific measurement of hearing ability. It involves determining the quietest sounds a person can detect (hearing thresholds) across the audible range. Audiometry is a central tool in audiology and otolaryngology, helping to diagnose hearing loss, assess its degree and type, monitor changes over time, and guide interventions such as hearing aid fitting.

Most common forms of audiometry are behavioral tests, where the patient actively responds to sounds. Pure-tone audiometry measures thresholds for ordinary air-conduction sounds through headphones or insert earphones and, if needed, bone-conduction through a bone vibrator to assess inner-ear function. Speech audiometry evaluates understanding of spoken words or sentences, producing measures such as the speech reception threshold and word recognition scores. Objective tests, such as tympanometry or otoacoustic emissions, can be used when behavioral responses are unreliable, as in infants or certain patients, and auditory brainstem response testing may be used for newborns or challenging cases.

Testing is typically conducted in a quiet, sound-treated room with calibrated equipment. The tester presents tones at various frequencies (commonly from 250 Hz to 8 kHz) and intensities, and the patient indicates detection. Thresholds are recorded in decibels hearing level (dB HL). Normal hearing generally falls within approximately −10 to 25 dB HL; higher thresholds indicate varying degrees of hearing loss. Air-conduction results determine overall sensitivity, while comparing air and bone conduction helps classify the loss as conductive, sensorineural, or mixed.

Applications include clinical diagnosis, fitting and verification of hearing aids, presbycusis evaluation, ototoxicity monitoring, and pediatric hearing screening. Limitations include dependence on patient cooperation and attention, age, language ability, and testing environment.