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PubMed · 1629475

Occluded-ear simulator with variable acoustic properties.

D P Egolf·W A Kennedy·V D Larson
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Abstract

Ear simulators were designed to replicate acoustical characteristics of the average adult ear. Due to variability of ear-canal geometry and eardrum impedance among individuals, the possibility of any one person exhibiting such "average" characteristics--especially if that person is a child and/or has a conductive pathology--is remote. Thus, ear simulators have been of only peripheral value when prescribing a hearing aid (a high output impedance device) to fit the acoustical requirements of a particular patient. Reported herein is development of a programmable artificial ear (PAE) that can account for individual differences in ear-canal geometry and eardrum impedance. It consists of a 2.0-cc coupler, microphone, amplifier, computer, PAE code, and a computer card and/or software for digitization and Fourier transformation. Required input data includes ear-canal dimensions, eardrum impedance, and output impedance of the hearing aid being tested. Sound-pressure recordings produced in the 2.0-cc coupler by the hearing aid are adjusted by the computer to what they would have been had the recordings been made at the eardrum of a particular patient wearing the same hearing aid. Good agreement was observed between experiment and theory for one test case involving a totally occluding miniature earphone.

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Acoustic Impedance TestsAcousticsEarEar CanalElectronics, MedicalHearing AidsHumansMaterials TestingModels, BiologicalPressureSignal Processing, Computer-AssistedSoftwareSoundJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

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D P Egolf, W A Kennedy, V D Larson. 1992. Occluded-ear simulator with variable acoustic properties.. https://doi.org/10.1121/1.402962

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