Signal injection coupling into the human vocal tract for robust audible and inaudible voice recognition

A method of minimizing degradation in the accuracy or speed of speech-recognition of a first speaker's speech or utterance caused by at least one second interfering background speaker, voice, or sound, said method comprising:

• coupling artificial acoustic excitation, directly or indirectly, into the vocal tract of the first speaker;
• allowing said first speaker to audibly speak in the potential acoustic presence of said at least one second background speaker or sound, thereby modifying or modulating said first speaker's artificial acoustic excitation as well as said first speaker's natural excitation;
• and
• processing at least a portion of said first speaker's artificially-produced acoustic output by a speech recognition means, said speech recognition means comprising:
• means for representation, modeling or classification, and searching of artificially excited speech signals or signal components;
• means for representation, modeling or classification, and searching of naturally excited speech signals or signal components;
• at least one of said searching means having access to at least one of an acoustic model, lexical model or language model;
• and
• at least one training means;
• wherein said first speaker's output is known to be that of said first speaker due to its identifiable artificial acoustic content,
• or wherein said second speaker's or sound's interfering output is ignored or rejected because it does not contain first speakers identifying artificial excitations.

A method of providing a speech-recognition based security function for user identification or validation comprising:

• (a) coupling, directly or indirectly, an artificial acoustic exciter into a user's vocal tract;
• (b) having the user speak, articulate or mouth an utterance wherein said utterance, at least in part, comprises a portion of the artificial excitation as-modified or modulated by said user's vocal tract;
• (c) applying speech recognition processing means to identify or validate said user, said means processing at least a portion of said artificially excited speech, utterance or signal-representation thereof;
• and
• (d) storing information relating to at least one characteristic of said user's vocal tract, or of its function, being used in said user identification or validation process, wherein said speech-recognition processing includes processing said modified acoustic excitation through representation, modeling or classification or both, and searching to produce identified words.