User barge-in enablement in large vocabulary speech recognition systems

• US 6,246,986 B1
• Filed: 12/31/1998
• Issued: 06/12/2001
• Est. Priority Date: 12/31/1998
• Status: Expired due to Term

• Current Assignee: Nuance Communications, Inc. (Microsoft Corporation)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Ammicht, Egbert, Gorin, Allen Louis
• Primary Examiner(s): Dorvil, Richemond
• Assistant Examiner(s): Nolan, Daniel A.
• Application Number:
  US09/223,945
• Time in Patent Office: 894 Days
• Field of Search: 704/231, 704/233, 704/270, 704/272, 704/275, 704/253, 704/254, 704/251, 704/244, 704/228, 704/214
• US Class Current: 704/270
• CPC Class Codes: G10L 15/22 Procedures used during a speech recognition process, e.g. man-machine dialogue
• CPC Class Codes: G10L 2015/088 Word spotting

Abstract

An interactive voice response unit which provides beneficial operation by including means to handle unconstrained input such as natural speech and to allow barge-in includes a prompter, a recognizer of speech signals, a meaningful phrase detector and classifier, and a turn-taking module, all under control of a dialog manager. In the course of listening to user input while outputting a voiced message, the voice response unit processes the received signal and ascertains whether it is receiving an utterance that is intended to interrupt the prompt, or merely noise or an utterance that is not meant to be used by the arrangement. The unit is sensitive to the speed and context of the speech provided by the user and is thus able to distinguish between a situation where a speaker is merely pausing and a situation where a speaker is done speaking.

Claims

1. An interactive voice response unit (VRU) including a telecommunication port, a prompt unit, and a controller that controls at least one prompt that is delivered by said prompt unit to said port, the improvement comprising:

a recognizer coupled to said port that discards input signals that fail to meet usefulness criteria; and

a phrase detector responsive to output signals of said recognizer and to control signals from said controller, developing detected meaningful phrases supplying data to said controller that corresponds to said meaningful phrases.

2. The VRU of claim 1 where said recognizer accepts unconstrained speech signal as a signal that meets said usefulness criteria.

3. The VRU of claim 1 where said recognizer accepts natural speech signal as a signal that meets said usefulness criteria.

4. The VRU of claim 1 where said recognizer accepts a string of DTMF signals as a signal that meets said usefulness criteria.

5. The VRU of claim 1 where said recognizer is adapted to receive digital signals at said port.

6. The VRU of claim 1 where said recognizer is adapted to receive analog signals at said port.

7. The VRU of claim 1 where said recognizer is adapted to receive an analog signal at said port that results from a digital signal modulating an analog signal.

8. The VRU of claim 1 where said input signals are DTMF signals.

9. The VRU of claim 7 where said modulation is modem-created modulation.

10. The VRU of claim 1 where said recognizer accepts unconstrained speech signals as well as DTMF signals as signals that meet said useful criteria.

11. The VRU of claim 1 where said recognizer includes an echo canceler that is responsive to input signals received at said port from a telecommunication network, and to output signals that said prompt unit sends to said telecommunication network via said port.

12. The VRU unit of claim 1 where said recognizer performs its functions while said prompt unit outputs a prompt signal to a telecommunication network via said port.

13. The VRU of claim 12 where said controller directs said prompt unit to cease sending said prompt signal when said detector supplies data to said controller that represents a useful phrase response received from said telecommunication network to said prompt signal.

14. The VRU of claim 1 where said phrase detector analyzes a rate at which words are detected, and lengths of silences between detected words, to control a determination that a response is completed.

15. The VRU of claim 1 where the detection in said phrase detector is carried out through word spotting.

16. The VRU of claim 14 where said phrase detector also analyzes inflection of detected words.

17. The VRU of claim 1 where said phrase detector employs detected words and detected silences between words to ascertain likelihood that useful input at said port has ended.

18. The VRU of claim 1 where said phrase detector comprises:

a meaningful phrase detector responsive to said recognizer that translates meaningful phrases found in said output signals of said recognizer into tasks to be provided to said controller, and

a turn-taking module responsive to output signals detected by said meaningful phrase detector, where said turn-taking module ascertains rate at which said meaningful phrase detector detects significant signal segments.

19. The VRU of claim 1 where said phrase detector comprises:

a meaningful phrase detector responsive to said recognizer that translates meaningful phrases found in said output signals of said recognizer into tasks to be provided to said controller, and

a turn-taking module responsive to output signals detected by said meaningful phrase detector, where said turn-taking module ascertains lengths of silences between significant signal segments detected by said meaningful phrase detector and provided to said turn-taking module.

20. The VRU of claim 1 where said phrase detector comprises:

a meaningful phrase detector responsive to said recognizer that translates meaningful phrases found in said output signals of said recognizer into tasks to be provided to said controller, and

a turn-taking module responsive to output signals detected by said meaningful phrase detector, where said turn-taking module ascertains inflections at which said meaningful phrase detector detects significant signal segments.

21. The VRU of claim 18 where said significant signal segments are words or DTMF signals representative of digits.

22. The VRU of claim 18 where said translating of meaningful phrases is controlled by signals developed by said turn-taking module from said ascertainment of rate at which said meaningful phrase detector detects significant signal segments.

23. The VRU of claim 18 where said turn-taking module controls said meaningful phrase detector.

24. The VRU of claim 18 where said controller provides control signals to said turn-taking module.

25. The VRU of claim 18 where said controller provides control signals to said meaningful phrase detector.

26. The VRU of claim 18 where said turn-taking module determines from elapsed times without a received input from said meaningful phrase detector that said port has completed sending an input signal.

27. The VRU of claim 18 where said turn-taking module determines from grammatical construct of input provided by said meaningful phrase detector whether said port has completed sending an input signal.

28. The VRU of claim 18 where said turn-taking module determines from context of input provided by said meaningful phrase detector whether said port has completed sending an input signal.