Method for synthesizing speech

1. A method, operable in a computer system, for analyzing of speech, the method causing the computer system to execute the acts of:

inputting a speech signal;

obtaining a first harmonic of the speech signal,

determining a phase-difference (Δφ) between the speech signal and the first harmonic for centering a windowing function, wherein said phase difference is determined between a phase of a maximum amplitude of said speech signal and a phase zero of the first harmonic, wherein a zero-crossing of the first harmonic defines the phase zero of the first harmonic; and

outputting the phase difference to a memory for storage.

2. The method of claim 1 ,

wherein the determining comprises the act of determining a location of said maximum of the speech signal.

3. The method of claim 1 , whereby the speech signal is a diphone signal.

4. A computer readable medium storing a computer program product which when loaded into a computer system caused the computer system to perform a method in accordance with claim 1 .

5. The method of claim 1 , wherein the zero-crossing is a positive zero-crossing.

6. The method of claim 1 , further comprising the act of extracting diphones from the speech signal, wherein the obtaining act includes low-pass filtering of the diphones.

7. A method for synthesizing speech, the method, operable in a computer system, comprising the acts of:

windowing by a window function diphone samples obtained from a speech signal;

selecting the windowed diphone samples, wherein the window function is centered with respect to a phase angle which is determined as a phase difference between a phase of a maximum amplitude of said speech signal and a phase zero of a zero crossing of a first harmonic of the speech signal; and

concatenating the selected windowed diphone samples to form the synthesized speech; and

outputting the synthesized speech.

8. The method of claim 7 , the speech signal being a diphone signal.

9. The method of claim 7 , the window function being a raised cosine or a triangular window.

10. The method of claim 7 further comprising inputting of information being indicative of diphones and a pitch contour, the information forming the basis for selecting of the windowed diphone samples.

11. The method of claim 7 , wherein the information is provided from a language processing module of a text-to-speech system.

12. The method of claim 7 further comprising the acts of:

inputting of speech, and

windowing the speech by the window function to obtain the windowed diphone samples.

13. The method of claim 7 , wherein the window function is centered on the phase angle which is equal to the phase difference plus the phase zero.

14. The method of claim 7 , wherein the window function is be symmetric with respect to the phase angle.

15. The method of claim 7 , wherein the window function and the diphone samples that are windowed are offset by the phase difference.

16. A speech analysis device for analyzing a speech signal comprising:

a filter for obtaining a first harmonic of the speech signal, a processor for determining a phase difference (Δφ) between the speech signal and the first harmonic for centering a windowing function, wherein said phase difference is determined between a phase of a maximum amplitude of said speech signal and a phase zero (φ 0 ) of the first harmonic, wherein a zero-crossing of the first harmonic defines the phase zero.

17. The speech analysis device of claim 16 , wherein the speech signal is a diphone signal.

18. A speech synthesis device comprising a processor configured for:

selecting of windowed diphone samples of a speech signal, the diphone samples being windowed by a window function being centered with respect to a phase angle which is determined as a phase difference between the speech signal and a first harmonic of the speech signal, wherein said phase difference is determined between a phase of a maximum amplitude of said speech signal and a phase zero of the first harmonic of the speech, wherein a zero-crossing of the first harmonic defines the phase zero; and

concatenating the selected windowed diphone signals.

19. The speech synthesis device of claim 18 , wherein the speech signal is a diphone signal.

20. The speech synthesis device of claim 18 the window function being a raised cosine or a triangular window.

21. The speech synthesis device of claim 18 , wherein the processor is further configured to receive information indicative of diphones and a pitch contour, and to select the windowed diphones based on the information.

22. A text-to-speech system comprising:

a language processor for providing information being indicative of diphones and a pitch contour of a speech signal; and

a speech synthesizer configured to:

select windowed diphone samples based on the information, the diphone samples being windowed by a window function being centered with respect to a phase angle which is determined as a phase difference between a phase of a maximum amplitude of said speech signal and a first harmonic of the speech signal, wherein a zero-crossing of the first harmonic defines the phase zero; and

concatenate the selected windowed diphone samples.

23. The text-to-speech system of claim 22 , whereby the window function is a raised cosine or a triangular window.

24. A speech processing system comprising a processor configured to:

receive a signal comprising natural speech signal, window the natural speech signal by a window function being centered with respect to a phase angle determined as a phase difference between a phase of a maximum amplitude of said natural speech signal and a phase zero of the first harmonic of the natural speech signal to provide windowed diphone samples, wherein a zero-crossing of the first harmonic defines the phase zero,

process the windowed diphone samples, and

concatenate the selected windowed diphone samples.