Biomaterial Database

Multiple frequency tympanometry: effects of ear canal volume compensation on static acoustic admittance and estimates of middle ear resonance. 1993

J E Shanks, and R H Wilson, and N K Cambron

VA Medical Center, Long Beach, CA.

Three methods for compensating multiple frequency acoustic admittance measurements for ear canal volume were studied in 26 men with normal middle ear transmission systems. Peak compensated static acoustic admittance (magnitude of y) and phase angle (phi) were calculated from sweep frequency tympanograms (226-1243 Hz in 113 Hz increments). Of the procedures used to compensate for volume in rectangular form, the ear canal pressure used to estimate volume had the largest effect on the estimate of middle ear resonance. Median resonance was 800 Hz for admittance measurements compensated at 200 daPa versus 1100 Hz for measurements compensated at -350 daPa. The remaining two methods, compensation of susceptance only versus both susceptance and conductance and compensation using the minimum volume versus separate volumes at each frequency, did not affect estimates of middle ear resonance. Estimates of middle ear resonance from compensated phase angle measurements also were compared with estimates of resonance from admittance and phase difference curves. Although resonance could not be estimated from the phase difference curve, resonance estimated from the admittance difference curve agreed with the estimate from compensated phase angle.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D004424	Ear Canal	The narrow passage way that conducts the sound collected by the EAR AURICLE to the TYMPANIC MEMBRANE.	Auditory Canal, External,External Acoustic Canal,External Acoustic Meatus,External Auditory Canal,External Ear Canal,Acoustic Canal, External,Acoustic Canals, External,Acoustic Meatus, External,Auditory Canals, External,Canal, Ear,Canal, External Ear,Canals, Ear,Canals, External Ear,Ear Canal, External,Ear Canals,Ear Canals, External,External Acoustic Canals,External Auditory Canals,External Ear Canals
D004432	Ear, Middle	The space and structures directly internal to the TYMPANIC MEMBRANE and external to the inner ear (LABYRINTH). Its major components include the AUDITORY OSSICLES and the EUSTACHIAN TUBE that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat.	Tympanic Cavity,Tympanum,Middle Ear,Cavities, Tympanic,Cavity, Tympanic,Ears, Middle,Middle Ears,Tympanic Cavities,Tympanums
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000158	Acoustic Impedance Tests	Objective tests of middle ear function based on the difficulty (impedance) or ease (admittance) of sound flow through the middle ear. These include static impedance and dynamic impedance (i.e., tympanometry and impedance tests in conjunction with intra-aural muscle reflex elicitation). This term is used also for various components of impedance and admittance (e.g., compliance, conductance, reactance, resistance, susceptance).	Audiometry, Impedance,Electroacoustic Impedance Tests,Impedance Tests, Acoustic,Tympanometry,Acoustic Impedance Test,Electroacoustic Impedance Test,Impedance Audiometry,Impedance Test, Acoustic,Impedance Test, Electroacoustic,Impedance Tests, Electroacoustic,Test, Acoustic Impedance,Test, Electroacoustic Impedance,Tests, Acoustic Impedance,Tests, Electroacoustic Impedance
D000162	Acoustics	The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)	Acoustic
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D013067	Speech Perception	The process whereby an utterance is decoded into a representation in terms of linguistic units (sequences of phonetic segments which combine to form lexical and grammatical morphemes).	Speech Discrimination,Discrimination, Speech,Perception, Speech