04187413 is referenced by 81 patents and cites 3 patents.

In an illustrated embodiment a behind-the-ear hearing aid includes a microphone, an amplifier-low pass filter circuit, an analog to digital converter, a digital integrated circuit arithmetic and logic unit for implementing a n-th order transfer function in the Z domain, a digital to analog converter and an output transducer, for producing the desired sound response. A memory multiplexer is provided for loading of the multiplier coefficients necessary to adapt the transfer function circuit to essentially any class of hearing deficiency into an erasable programmable read only memory (EPROM). The structure is such that the coefficient memory may be loaded after the standard universal hearing aid has been completely assembled, and indeed the hearing aid may be reprogrammed as needed after a period of use, essentially without disassembly.

Title
Hearing aid with digital processing for: correlation of signals from plural microphones, dynamic range control, or filtering using an erasable memory
Application Number
5/894348
Publication Number
4187413
Application Date
April 7, 1978
Publication Date
February 5, 1980
Inventor
Ludwig M Moser
Estenfeld
DE
Agent
Hill Van Santen Steadman Chiara & Simpson
Assignee
Siemens Aktiengesellschaft
DE
IPC
H04R 25/00
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