otometre

An otometre (also otometer) is a device historically used to measure aspects of the ear’s function. The term appears in older and regional medical literature, and in modern English the functions it describes are typically covered by more specific instruments such as audiometers, tympanometers, and devices that measure otoacoustic emissions. The word etymology combines Greek oto- “ear” and metron “measure.”

Historically, otometres were used to assess auditory sensitivity or middle-ear mechanics by delivering controlled sounds to the external ear and recording responses from the ear canal or tympanic membrane. Some devices emphasized impedance and compliance of the tympanic membrane (tympanometry-like measurements), while others aimed to estimate hearing thresholds, similar to an audiometer.

In contemporary practice the explicit term otometre is uncommon, and clinicians refer to the appropriate category of instrument instead. Related technologies include audiometry for hearing thresholds, tympanometry for middle-ear admittance, and otoacoustic-emission testing for cochlear function. When encountered in historical texts, otometre is usually described as a general ear-measuring instrument rather than a single standardized device.

Design and operation of devices historically labeled as otometres typically involved a calibrated sound source, a probe or ear tip, a microphone for in-ear signal capture, and a readout of measurements. Calibration across frequencies and sound levels was essential to ensure accurate results. The term reflects an older view of a class of instruments rather than a current, singular device.