Apparatus and method for controlling rate of playback of audio data

• US 20020010916A1
• Filed: 02/12/2001
• Published: 01/24/2002
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Thong, Jean-Manuel Van, Pan, Davis
• Granted Patent: US 6,490,553 B2
• Time in Patent Office: Days
• US Class Current: 725/1
• CPC Class Codes: G10L 15/26 Speech to text systems G10L15/08 takes precedence
• CPC Class Codes: H04N 5/278 Subtitling

Abstract

The disclosed method and apparatus controls the rate of playback of audio data corresponding to a stream of speech. Using speech recognition, the rate of speech of the audio data is determined. The determined rate of speech is compared to a target rate. Based on the comparison, the playback rate is adjusted, i.e. increased or decreased, to match the target rate.

Claims

1. A method for controlling rate of playback of audio-data corresponding to a stream of speech, comprising the computer implemented steps of:

using speech recognition, calculating rate of speech in the stream of speech;

comparing the calculated rate of speech with a target rate; and

based on said comparing, adjusting rate at which the audio data is played back.

2. A method as claimed in claim 1 wherein said step of using speech recognition includes:

determining a sequence of linguistic units indicative of the stream of speech; and

for each determined linguistic unit in the sequence, determining time of occurrence of the linguistic unit in the stream of speech.

3. A method as claimed in claim 2 wherein the step of calculating rate of speech includes computing linguistic unit rate.

4. A method as claimed in claim 1 wherein the step of comparing includes determining if the calculated rate of speech is greater than the target rate;

and

the adjusting step decreases the rate of playback of the audio data.

5. A method as claimed in claim 1 wherein the step of comparing includes determining if the calculated rate of speech is less than the target rate;

and

the adjusting step increases the rate of playback of the audio data.

6. A method as claimed in claim 1 wherein the step of comparing uses a predefined value as the target rate.

7. A method as claimed in claim 1 wherein the step of comparing uses a value indicative of transcription rate by a transcriber of the audio data, as the target rate.

8. A method as claimed in claim 1 wherein the step of adjusting includes altering the rate of playback of the audio data in a manner free of changing pitch of the corresponding speech.

9. A method as claimed in claim 8 wherein the step of altering employs a frequency domain technique.

10. A method as claimed in claim 8 wherein the step of altering employs a time domain technique.

11. A method as claimed in claim 10 wherein the time domain technique includes interval sampling.

12. A method as claimed in claim 10 wherein the time domain technique includes silence removal.

13. Apparatus for controlling rate of playback of audio-data corresponding to a stream of speech, comprising

a calculation unit for calculating rate of speech in the stream of speech using speech recognition;

and

a playback rate adjustment unit coupled to receive from the calculation unit the calculated rate of speech, the playback rate adjustment unit comparing the calculated rate of speech with a target rate, and based on said comparing, adjusting rate at which the audio data is played back.

14. Apparatus as claimed in claim 13 wherein said calculation unit uses speech recognition to determine a sequence of linguistic units indicative of the stream of speech, and for each determined linguistic unit in the sequence, determines time of occurrence of the linguistic unit in the stream of speech.

15. Apparatus as claimed in claim 14 wherein the calculation unit computes linguistic unit rate.

16. Apparatus as claimed in claim 13 wherein the playback rate adjustment unit determines if the calculated rate of speech is greater than the target rate and, if so, decreases the rate of playback of the audio data.

17. Apparatus as claimed in claim 13 wherein the playback rate adjustment unit determines if the calculated rate of speech is less than the target rate and if so, increases the rate of playback of the audio data.

18. Apparatus as claimed in claim 13 wherein the playback rate adjustment unit uses a predefined value as the target rate.

19. Apparatus as claimed in claim 13 wherein the the playback rate adjustment unit uses a value indicative of transcription rate by a transcriber of the audio data playback, as the target rate.

20. Apparatus as claimed in claim 13 wherein the playback rate adjustment unit alters the rate of playback of the audio data in a manner free of changing pitch of the corresponding speech.

21. Apparatus as claimed in claim 20 wherein the playback rate adjustment unit employs a time domain technique.

22. Apparatus as claimed in claim 20 wherein the playback rate adjustment unit employs a frequency domain technique.

23. Apparatus as claimed in claim 22 wherein the time domain technique includes interval sampling.

24. Apparatus as claimed in claim 22 wherein the time domain technique includes silence removal.