title: Experimental determination of cascade parameters of a hearing-aid microphone via the two-load method.
abstract: Presented in this article is a computer-aided experimental method for obtaining the cascade parameters of the two-port model of a miniature hearing-aid microphone. The method is an adaptation of the "two-load" method [D.P. Egolf and R.G. Leonard, J. Acoust. Soc. Am. 62, 1013-1023 (1977)] to acoustoelectric, rather than electroacoustic, transducers. The cascade parameters of a particular microphone, determined by this method, were within 2.5 dB of the manufacturer's published open-circuit sensitivity data. In an attempt to further verify the numerical cascade-parameter data, a two-port model of the microphone was used to simulate experimental voltages developed across two different complex electrical load impedances attached to the microphone. The results showed experimental/simulation differences of no greater than 3.0 dB at any frequency. The two-port microphone model and associated cascade parameters are currently being incorporated into a computer-based plan for mathematical simulation of an entire in situ hearing aid.
authors.affiliation: Department of Electrical Engineering, University of Wyoming, Laramie 82071.
authors.forename: D P
authors.initials: DP
authors.lastname: Egolf
authors.forename: B T
authors.initials: BT
authors.lastname: Haley
authors.forename: K M
authors.initials: KM
authors.lastname: Bauer
authors.forename: H C
authors.initials: HC
authors.lastname: Howell
authors.forename: V D
authors.initials: VD
authors.lastname: Larson
mesh_terms: D004581:Electronics; D006310:Hearing Aids; D008433:Mathematics; D008962:Models, Theoretical