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Hearing aid malfunction detection systemA malfunction detection system for detecting malfunctions in electrical signal processing circuits is disclosed. Malfunctions of a hearing aid in the form of frequency distortion and/or inadequate amplification by the hearing aid amplifier, as well as weakening of the hearing aid power supply are detectable. A test signal is generated and a timed switching circuit periodically applies the test signal to the input of the hearing aid amplifier in place of the input signal from the microphone. The resulting amplifier output is compared with the input test signal used as a reference signal. The hearing aid battery voltage is also periodically compared to a reference voltage. Deviations from the references beyond preset limits cause a warning system to operate.
Document ID
19780002432
Acquisition Source
Legacy CDMS
Document Type
Other - Patent
Authors
Kessinger, R. L. (Martin Marietta Corp. Denver, United States)
Date Acquired
September 3, 2013
Publication Date
September 20, 1977
Subject Category
Electronics And Electrical Engineering
Report/Patent Number
Patent Number: US-PATENT-4.049,930
Patent Number: NASA-CASE-MSC-14916-1
Patent Application Number: US-PATENT-APPL-SN-739914
Accession Number
78N10375
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-PATENT-4.049,930|NASA-CASE-MSC-14916-1
Patent Application
US-PATENT-APPL-SN-739914

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