Speech-responsive voice messaging system and method

• US 6,385,304 B1
• Filed: 02/14/2000
• Issued: 05/07/2002
• Est. Priority Date: 03/24/1997
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Avaya Technology Corporation Miami Lakes FLA US
• Inventors: Hunt, Peter, Grajski, Kamil, Rub, Leonardo, Albright, Susannah
• Primary Examiner(s): WEAVER, SCOTT LOUIS
• Application Number:
  US09/503,314
• Time in Patent Office: 813 Days
• Field of Search: 379/67.1, 379/88.01, 379/88.02, 379/88.03, 379/88.04, 379/88.08, 379/88.22, 379/88.23, 379/88.24, 704/200, 704/231, 704/246, 704/251, 704/270
• US Class Current: 379/88.01
• CPC Class Codes: G10L 15/22 Procedures used during a speech recognition process, e.g. man-machine dialogue

Abstract

A system and method for speech-responsive voice messaging, in which a Speech-Responsive Voice Messaging System (SRVMS) preferably provides a hierarchically-simple speech user interface (UI) that enables subscribers to use speech to specify commands such as mailboxes, passwords, and digits. The SRVMS generates and evaluates candidate results. The SRVMS invokes a speech UI navigation operation or a voice messaging operation according to the outcome of the evaluation of the candidate results. In the preferred embodiment, the SRVMS determines whether the candidate results are good, questionable, or bad; and whether two or more candidate results are ambiguous due to a likelihood that each such result could be a valid command. If the candidate results are questionable or ambiguous, an ambiguity resolution UI prompts the subscriber to confirm whether the best candidate result is what the subscriber intended. In response to repeated speech recognition failures, the SRVMS transfers the subscriber to a Dual Tone Multi Frequency (DTMF) UI. Transfer to the DTMF UI is also performed in response to detection of predetermined DTMF signals issued by the subscriber while the speech UI is in context. The SRVMS provides a logging unit and a reporting unit which operate in parallel with the speech UI, in a manner that is transparent to subscribers. The logging unit directs the selective logging of subscriber utterances, and the reporting unit selectively generates and maintains system performance statistics on multiple detail levels.

Claims

1. A method of recognizing one or more audible instructions from a user, the method comprising the steps of:

a. selecting a speech parameter block, wherein the speech parameter block comprises a data structure having a plurality of data fields, wherein the plurality of data fields includes a first data field for storing a plurality of speech recognition parameters and a second data field for storing a plurality of commands;

b. audibly prompting the user for a response;

c. detecting the response, wherein the response is one selected from a group consisting of an audible utterance by the user and a dual tone multi frequency signal input actuated by the user;

d. performing a speech recognition operation on the audible utterance guided by the plurality of speech recognition parameters to determine a potential match between the audible utterance and one or more commands stored in the second data field; and

e. scoring the potential match relative to the plurality of speech recognition parameters stored in the speech parameter block to produce a score.

2. The method according to claim 1 further comprising the step of providing a template library having a plurality of speech templates, each speech template corresponding to one of the plurality of commands, wherein the template library facilitates the step of performing a speech recognition operation.

3. The method according to claim 2 wherein the plurality of speech templates includes a plurality of speaker independent speech templates.

4. The method according to claim 3 wherein the speech recognition operation includes a speaker independent speech recognition operation.

5. The method according to claim 4 wherein the plurality of speech templates includes a plurality of speaker dependent speech templates.

6. The method according to claim 5 wherein the speech recognition operation includes a speaker dependent speech recognition operation.

7. The method according to claim 1 wherein the speech parameter block further includes a third data field for storing a plurality of quality threshold parameters.

8. The method according to claim 7 further comprising the step of evaluating the score relative to the plurality of quality threshold parameters.

9. The method according to claim 8 wherein the step of evaluating the score includes the step of designating the score with one of a plurality of confidence labels, wherein each confidence label indicates a level of confidence in the potential match.

10. The method according to claim 9 wherein the step of evaluating the score further includes the steps of:

a. setting a confirmation indicator if the score is designated with a first confidence label; and

b. setting a repeat speech recognition indicator if the score is designated with a second confidence label.

11. The method according to claim 10 further comprising the step of performing a confirmation operation if the confirmation indicator is set.

12. The method according to claim 11 wherein the step of performing a confirmation operation includes the steps of:

a. selecting a confirmation speech parameter block, wherein the confirmation speech parameter block stores a plurality of parameters for guiding the confirmation operation;

b. generating an appropriate confirmation voice prompt to the user;

c. detecting a confirmation utterance by the user; and

d. evaluating the confirmation utterance.

13. The method according to claim 12 wherein the step of evaluating the confirmation utterance includes the steps of:

a. performing a confirmation speech recognition operation on the confirmation utterance guided by the plurality of parameters; and

b. determining whether an unsuccessful confirmation condition exists.

14. The method according to claim 13 further comprising the step of repeating the step of performing a confirmation operation upon the occurrence of the unsuccessful confirmation condition.

15. The method according to claim 10 further comprising the step of initiating a second audible prompt to the user if the repeat speech recognition indicator is set.

16. The method according to claim 1 further comprising the step of performing a dual tone multi frequency recognition operation on the dual tone multi frequency signal input.

17. A voice messaging system capable of recognizing one or more voice instructions from a user, the voice messaging system comprising:

a. a speech parameter block library having a plurality of speech parameter blocks for regulating voice communication with the user, wherein each speech parameter block includes a data structure having a plurality of data fields;

b. means coupled to the speech parameter block library for selecting an appropriate one of the plurality of speech parameter blocks to control voice communication with the user;

c. means coupled to the speech parameter block library for audibly prompting the user for a response;

d. means coupled to the speech parameter block library for detecting the response, wherein the response is one selected from a group consisting of an utterance by the user and a dual tone multi frequency signal input actuated by the user; and

e. means coupled to the speech parameter block library for performing a speech recognition operation on the utterance.

18. The voice messaging system according to claim 17 further comprising means for performing a dual tone multi frequency recognition operation on the dual tone multi frequency signal input.

19. The voice messaging system according to claim 17 wherein the plurality of data fields of each speech parameter block include a first data field for storing a plurality of speech recognition parameters and a second data field for storing a plurality of commands, wherein each command corresponds to a voice messaging function.

20. The voice messaging system according to claim 19 wherein the means for performing a speech recognition operation determines a potential match between the utterance and one or more of the plurality of commands stored in the second data field by utilizing the plurality of speech recognition parameters.

21. The voice messaging system according to claim 20 further comprising means for scoring the potential match relative to the plurality of speech recognition parameters stored in the first data field to produce a score.

22. The voice messaging system according to claim 21 wherein the plurality of data fields of each speech parameter block further include a third data field for storing a plurality of quality threshold parameters.

23. The voice messaging system according to claim 22 further comprising means for evaluating the score relative to the plurality of quality threshold parameters such that the score is designated with one of a plurality of confidence labels, wherein each confidence label indicates a level of confidence in the potential match.

24. The voice messaging system according to claim 23 further including:

a. a confirmation indicator which is set if the score is designated with a first confidence label; and

b. a repeat speech recognition indicator which is set if the score is designated with a second confidence label.

25. The voice messaging system according to claim 24 further including means for performing a confirmation operation if the confirmation indicator is set.

26. The voice messaging system according to claim 25 wherein the means for performing a confirmation operation comprises:

a. means for transferring to a confirmation speech parameter block, wherein the confirmation speech parameter block stores a plurality of confirmation parameters;

b. means for generating an appropriate confirmation voice prompt to the user;

c. means for detecting a confirmation utterance by the user; and

d. means for evaluating the confirmation utterance.

27. The voice messaging system according to claim 26 wherein the means for evaluating the confirmation utterance includes:

a. means for performing a confirmation speech recognition operation on the confirmation utterance by applying the plurality of confirmation parameters; and

b. means for determining whether an unsuccessful confirmation condition exists.

28. The voice messaging system according to claim 27 wherein the means for performing a confirmation operation performs the confirmation operation upon the occurrence of the unsuccessful confirmation condition.

29. The voice messaging system according to claim 24 wherein the means for audibly prompting the user prompts the user for an additional response if the repeat speech recognition indicator is set.

30. The voice messaging system according to claim 17 further comprising a template library having a plurality of speech templates, each speech template corresponding to one of the plurality of commands, wherein the template library facilitates performing the speech recognition operation on the utterance.

31. The voice messaging system according to claim 30 wherein the plurality of speech templates includes a plurality of speaker independent speech templates.

32. The voice messaging system according to claim 31 wherein the speech recognition operation includes a speaker independent speech recognition operation.

33. The voice messaging system according to claim 32 wherein the plurality of speech templates includes a plurality of speaker dependent speech templates.

34. The voice messaging system according to claim 33 wherein the speech recognition operation includes a speaker dependent speech recognition operation.