Modification of voice waveforms to change social signaling

• US 20080044048A1
• Filed: 09/06/2007
• Published: 02/21/2008
• Est. Priority Date: 09/06/2007
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Pentland, Alex
• Granted Patent: US 8,484,035 B2
• Time in Patent Office: Days
• US Class Current: 381/315
• CPC Class Codes: H04S 1/007 in which the audio signals are in digital form data reduction aspects thereof based on psychoacoustics G10L19/02

Abstract

A method of altering a social signaling characteristic of a speech signal. A statistically large number of speech samples created by different speakers in different tones of voice are evaluated to determine one or more relationships that exist between a selected social signaling characteristic and one or more measurable parameters of the speech samples. An input audio voice signal is then processed in accordance with these relationships to modify one or more of controllable parameters of input audio voice signal to produce a modified output audio voice signal in which said selected social signaling characteristic is modified. In a specific illustrative embodiment, a two-level hidden Markov model is used to identify voiced and unvoiced speech segments and selected controllable characteristics of these speech segments are modified to alter the desired social signaling characteristic.

Claims

1. A method of altering a selected social signaling characteristic of a speech signal comprising, in combination, the steps of:

evaluating a statistically large number of speech samples created by different speakers in different tones of voice to determine one or more relationships that exist between a selected social signaling characteristic and one or more measurable parameters of said speech samples, and

processing an input audio voice signal in accordance with said relationship to modify one or more of said parameters of said input audio voice signal to produce a modified output audio voice signal in which said selected social signaling characteristic is modified.

2. The method of altering a selected social signaling characteristic of a speech signal as set forth in claim 1 in which said social signaling characteristic is selected from a group comprising:

interest, attraction, attentiveness, friendliness, determination, submissiveness, and persuasiveness.

3. The method of altering a selected social signaling characteristic of a speech signal as set forth in claim 1 wherein said measurable parameters are selected from a group comprising activity level, speaking rate, engagement, emphasis, pause length entropy, and mirroring,

4. The method of altering a selected social signaling characteristic of a speech signal as set forth in claim 3 in which said social signaling characteristic is selected from a group comprising:

interest, attraction, attentiveness, friendliness, determination, submissiveness, and persuasiveness.

5. The method of altering a selected social signaling characteristic of a speech signal as set forth in claim 1 wherein at least some of said measurable parameters are parameters of voiced segments of said speech samples and wherein step of processing includes modifying at least one of said parameters of voiced segments of said input audio voice signal.

6. The method of altering a selected social signaling characteristic of a speech signal as set forth in claim 5 wherein others of said measurable parameters are parameters of unvoiced segments of said speech samples and wherein step of processing includes modifying at least one of said parameters of unvoiced segments of said input audio voice signal.

7. The method of altering a selected social signaling characteristic of a speech signal as set forth in claim 6 wherein said social signaling characteristic is selected from a group comprising:

interest, attraction, attentiveness, friendliness, determination, submissiveness, and persuasiveness.

8. A system for modifying a speech signal to alter one or more of its social signaling characteristics comprising, in combination,

a source of an audio input signal,

means for analyzing said audio input signal to identify segments of said audio signal which represent specific spoken utterances, and

a signal processor for modifying said audio signal to alter one or more attributes of at least selected ones of said segments to form an audio output signal.

9. The system for modifying a speech signal to alter one or more of its social signaling characteristics as set forth in claim 8 wherein said one or more social signaling characteristics is persuasiveness and wherein said signal processor alters the duration of said selected ones of said segments.

10. The system for modifying a speech signal to alter one or more of its social signaling characteristics as set forth in claim 9 wherein said signal processor alters the duration of said selected ones of said segments without significant change in the spectral characteristics of selected ones of said segments.

11. The system for modifying a speech signal to alter one or more of its social signaling characteristics as set forth in claim 10 wherein said signal processor employs a phase vocoder to expand or contract the duration of said selected ones of said segments.

12. The system for modifying a speech signal to alter one or more of its social signaling characteristics as set forth in claim 10 wherein said signal processor alters the duration of only those segments having a duration longer than a predetermined threshold duration.

13. The system for modifying a speech signal to alter one or more of its social signaling characteristics as set forth in claim 9 wherein said signal processor further regulates the volume of said segments.

14. The system for modifying a speech signal to alter one or more of its social signaling characteristics as set forth in claim 8 wherein said one or more social signaling characteristics is persuasiveness and wherein said signal processor regulates the volume of said selected ones of said segments.

15. Apparatus for automatically modifying one or more social signaling characteristics of an audio input signal to produce a modified audio output signal comprising, in combination,

a digital signal analyzer for determining the boundaries between speech segments and non-speech segments of said audio input signal,

a digital signal processor for modifying one or more controllable parameters of said speech segments to produce modified speech segments having one or more modified social signaling characteristics, and

output means for combining said modified speech segments with said non-speech segments to produce said modified audio output signal.

16. Apparatus for automatically modifying one or more social signaling characteristics of an audio input signal as set forth in claim 15 wherein said digital signal analyzer further determines the boundaries between voiced and unvoiced segments of said speech segments and wherein said digital signal processor modifies one or more controllable parameters of said voiced segments.

17. Apparatus for automatically modifying one or more social signaling characteristics of an audio input signal as set forth in claim 16 wherein said digital signal processor further modifies one or more controllable parameters of said unvoiced voiced segments.

18. Apparatus for automatically modifying one or more social signaling characteristics of an audio input signal as set forth in claim 15 further including means for determining and storing one or more relationships that exist between a given selected social signaling characteristic and at least one of said controllable parameters and wherein said digital signal processor modifies said at least one of said controllable parameters in accordance with at least one of said relationships to control said selected social signaling characteristic.

19. Apparatus for automatically modifying one or more social signaling characteristics of an audio input signal as set forth in claim 18 wherein said digital signal analyzer further determines the boundaries between voiced and unvoiced segments of said speech segments and wherein said digital signal processor modifies controllable parameters of said voiced segments.

20. Apparatus for automatically modifying one or more social signaling characteristics of an audio input signal as set forth in claim 19 wherein said digital signal processor further modifies one or more controllable parameters of said unvoiced voiced segments.