A VOICE MAIL SYSTEM WITH IMPROVED DETECTION AND CANCELLATION

A voice mail system (10) includes method and apparatus for muting a previously recorded audio signal upon detection of a DTMF signal to differentiate between recorded DTMF signals and valid DTMF commands. A DTMF signal detected after muting is recognized as an invalid command. The system (10) also i...

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Bibliographic Details
Main Authors HANSON, PAUL G, ROSAS, ROBIN R, O'BRIEN, DENNIS J, KLARQUIST, THOMAS D, NEPPLE, BRUCE C, PARK, MICHAEL C
Format Patent
LanguageEnglish
Published 17.04.1991
Edition4
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
TELEPHONIC COMMUNICATION
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Summary:A voice mail system (10) includes method and apparatus for muting a previously recorded audio signal upon detection of a DTMF signal to differentiate between recorded DTMF signals and valid DTMF commands. A DTMF signal detected after muting is recognized as an invalid command. The system (10) also includes method and apparatus for matching the impedance of a 2-to-4 wire converter (94) within the system (10) against the impedance of the outside telephone system (14) to improve the ability of the system (10) to detect the DTMF commands generated by a caller. Other features of the voice mail system (10) comprise apparatus for detecting the end of a message by recognizing call progress tones. The system also includes a message board in which each user of the system (10) can check its status and whether the user has a waiting message.
Bibliography:Application Number: EP19880311363