Accession Number : ADD003179

Title :   Helium Speech Decoder.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Dildy,Clell A , Jr

Report Date : 02 Dec 1975

Pagination or Media Count : 8

Abstract : The patent relates to a helium speech decoder of the type that may be used to an advantage by divers living, working, and communicating in and from deep water habitats. It includes a microphone, a digital-to-analog converter, a battery of pairs of shift registers, a like battery of select gate circuits, an analog-to-digital converter, and earphones. A programmable generator produces a plurality of control signals which are timely supplied to the aforementioned components as necessary to effect the concerted operation thereof in such manner as to cause a pitch scaling, reduction, or decoding of the human speech that is spoken in a pressurized helium-oxygen environment, without substantially changing the syllabic or word rate thereof. A filtered fundamental frequency of said human speech is optionally added to the decoded portion thereof to enhance the fidelity thereof.

Descriptors :   *Decoders, *Patents, Speech, Helium, Signal processing, Analog to digital converters, Digital to analog converters, Shift registers, Gates(Circuits)

Subject Categories : Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE