Glossary

Also: admittance, compliance

The ease with which acoustic energy flows into the middle-ear system. The inverse of impedance; the quantity plotted on a tympanogram.

See also: Acoustic impedance, Static admittance

The opposition the middle-ear system offers to the flow of acoustic energy. Determined by the balance of stiffness, mass and resistance.

See also: Acoustic admittance

Also: stapedial reflex

An involuntary, bilateral contraction of the stapedius muscle in response to a sufficiently loud sound, detectable as a change in middle-ear immittance.

See also: Reflex decay, Acoustic reflex threshold

Also: ART

The lowest stimulus level that elicits a reliable acoustic reflex, typically measured at 500, 1000, 2000 and 4000 Hz.

See also: Acoustic reflex

A characteristic dip in bone-conduction thresholds around 2 kHz, classically associated with otosclerosis.

See also: Otosclerosis

Also: ECV, Vea

An estimate of the air volume between the probe tip and the tympanic membrane, used to distinguish flat-trace causes such as effusion, occlusion and perforation.

The degree to which the acoustic reflex contraction is sustained during a prolonged stimulus. A fall of 50% or more within five seconds is a positive (abnormal) result.

See also: Acoustic reflex

Also: peak compliance, peak admittance

The peak height of the tympanogram above the ear-canal baseline — the maximum mobility of the middle-ear system.

See also: Acoustic admittance

Also: TPP

The ear-canal pressure at which admittance is greatest; an estimate of middle-ear pressure.

Also: gradient

The pressure interval across the tympanogram at 50% of peak height; a measure of how sharp or broad the peak is.