Monitoring text to speech output to effect control of barge-in

• US 7,062,440 B2
• Filed: 05/31/2002
• Issued: 06/13/2006
• Est. Priority Date: 06/04/2001
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Tucker, Roger Cecil Ferry, Brittan, Paul St John
• Primary Examiner(s): Young, Wayne
• Assistant Examiner(s): Opsasnick, Michael N.
• Application Number:
  US10/158,104
• Publication Number:
  US 20020184031A1
• Time in Patent Office: 1,474 Days
• Field of Search: 704/266, 704/275, 379/208.01, 379 8801- 8804
• US Class Current: 704/266
• CPC Class Codes: G10L 13/00 Speech synthesis; Text to speech systems
• CPC Class Codes: G10L 15/22 Procedures used during a speech recognition process, e.g. man-machine dialogue
• CPC Class Codes: G10L 2015/228 of application context

Abstract

A speech system has a speech input channel including a speech recognizer, and a speech output channel including a text-to-speech converter. Associated with the input channel is a barge-in control for setting barge-in behavior parameters determining how the apparatus handles barge-in by a user during speech output by the apparatus. In order to make the barge-in control more responsive to the actual speech output from the output channel, a barge-in prediction arrangement is provided that is responsive to feature values produced during the operation of the text-to-speech converter to produce indications as to the most likely barge-in points. The barge-in control is responsive to these indications to adjust at least one of the barge-in behavior parameters for periods corresponding to the most likely barge-in points.

Claims

1. Speech apparatus comprising:

a speech input channel including a speech recogniser;

a speech output channel including a text-to-speech converter;

a barge-in prediction arrangement arranged to assess an overall quality of speech-form passages being produced by the text-to-speech converter from input text-form utterances whereby to produce barge-in prediction indications in correspondence to speech-form passages assessed as inadequate; and

a barge-in control for setting barge-in behaviour parameters for determining how the apparatus handles barge-in by a user during speech output by the apparatus, the barge-in control being arranged to be responsive to said barge-in prediction indications to adjust at least one said barge-in behaviour parameter for the corresponding speech-form passages assessed as inadequate,

the barge-in control being arranged to be responsive to the said indications to adjust at least one said barge-in behaviour parameter for periods corresponding to the most likely barge-in points.

2. Apparatus according to claim 1, wherein the text-to-speech converter is arranged to generate, in the course of converting a text-form utterance into a speech-form passage, values of predetermined features that are indicative of the overall quality of the speech-form passage, the barge-in prediction arrangement comprising:

a classifier arranged to be responsive to the feature values generated by the text-to-speech converter to provide a confidence measure of the speech-form passage concerned; and

a comparator for comparing confidence measures produced by the classifier against one or more stored threshold values, in order to determine when a said barge-in prediction indication is to be produced.

3. Apparatus according to claim 1, wherein the text-to-speech converter includes a concatenative speech generator which, in generating a speech-form passsage, produces an accumulated unit selection cost in respect of the speech units used to make up the speech-form passage;

the barge-in prediction arrangement comprising a comparator for comparing the selection cost produced by the speech generator against one or more stored threshold values, in order to determine when a said barge-in prediction indication is to be produced.

4. Apparatus according to claim 1, wherein the text-to-speech converter is arranged to be responsive to the generation of a said barge-in prediction indication to insert a pause in the corresponding speech-form passage.

5. Apparatus according to claim 1, wherein the barge-in control is arranged to respond to said barge-in prediction indication to set a said behaviour parameter such that any detected noise in the speech input channel is treated as barge-in during the corresponding speech-form passage, the barge-in control being arranged subsequently to reset this parameter such that noise in the speech input channel is only treated as a barge-in after it has been recognized as speech.

6. A method of controlling barge-in in speech apparatus that has both a speech input channel including a speech recogniser and a speech output channel including a text-to-speech converter;

the method comprising the steps of;

(a) automatically assessing overall quality of speech-form passages being produced by the text-to-speech converter from input text-form utterances whereby to produce barge-in prediction indications in correspondence to speech-form passages assessed as inadequate; and

(b) adjusting, for periods corresponding to the speech-form passages assessed as inadequate, as indicated by said barge-in prediction indications, at least one barge-in behaviour parameter that determines how the apparatus handles barge-in by a user during speech output by the apparatus.

7. A method according to claim 6, wherein the text-to-speech converter generates, in the course of converting a text-form utterance into a speech-form passage, values of predetermined features that are indicative of the overall quality of the speech-form passage, step (a) including:

using a classifier responsive to the feature values generated by the text-to-speech converter to provide a confidence measure of the speech-form passage concerned; and

comparing said confidence measures against one or more stored threshold values, in order to determine when a said barge-in prediction indication is to be produced.

8. A method according to claim 6, wherein the text-to-speech converter includes a concatenative speech generator which, in generating a speech-form passage, produces an accumulated unit selection cost in respect of the speech units used to make up the speech-form passage;

step (a) including comparing the selection cost produced by the speech generator against one or more stored threshold values, in order to determine when a said barge-in prediction indication is to be produced.

9. A method according to claim 6, comprising the further step of inserting, in response to the generation of a said barge-in prediction indication, a pause in the corresponding speech-form passage.

10. A method according to claim 6, wherein in step (b) a said behaviour parameter is adjusted such that any detected noise in the speech input channel is treated as a barge-in during the corresponding speech-form passage, this parameter being subsequently re-adjusted such that noise in the speech input channel is only treated as barge-in after it has been recognized as speech.