Accession Number:

AD0815816

Title:

POSITIVE VOICE OPERATED TRANSMITTER CONTROL.

Descriptive Note:

Final technical rept. 1 Mar 66-1 Mar 67,

Corporate Author:

WESTINGHOUSE DEFENSE AND ELECTRONIC SYSTEMS CENTER BALTIMORE MD AEROSPACE DIV

Personal Author(s):

Report Date:

1967-04-01

Pagination or Media Count:

86.0

Abstract:

Principal objectives of the Positive Voice Operated Transmitter Control Program were to investigate and develop techniques which will permit positive voice switching of a transmitter in the high acoustical noise conditions, typically encountered in a space capsule, aircraft cockpit, or flight line environment. The design guidelines for this program included the use of a single microphone and the exclusion of techniques in which the speech sensor is in direct contact with the operator. An investigation of several techniques, compatible with the microelectronic technology, was conducted. The most promising approach for providing reliable voice control of a transmitter was found to be a design which makes use of the peak-to-average distribution of the speech signals. Other basic approaches investigated, included techniques for exploiting the asymmetrical features of voiced speech and techniques for extracting the necessary speech information by using selective narrowband filters. The outputs of such filters are combined in a specific manner and used in conjunction with a particular detection criteria. Two prototype units were constructed and tested. Final performance of the system was evaluated in sound levels exceeding 130 dB, the design goal. A principal design feature of the developed voice switching system is that the system will not lock on in high noise ambients, which by their nature preclude intelligible communications.

Subject Categories:

  • Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE