PHONEME SIGNATURE CANDIDATES FOR SPEECH RECOGNITION

1 . A non-transitory computer readable storage medium to tangibly store instructions, which when executed by a computer, cause the computer to perform operations comprising:

at a computing device, determining base frequency for a speech signal;

calculating curvatures at extrema points based on a normalized phoneme function, wherein the normalized phoneme function is a function of a time period of a phoneme function and a value of the phoneme function;

comparing the calculated curvatures with reference curvatures of phonemes;

when a sequence of the calculated curvatures matches a sequence of the reference curvatures, identifying a corresponding phoneme.

2 . The computer readable storage medium of claim 1 , comprising instructions, which when executed by the computer cause the computer to perform operations further comprising:

dividing the speech signal into frames; and

comparing coordinates of the extrema points with reference coordinates of the phonemes; and

identifying the corresponding phoneme, comprising:

identifying the corresponding phoneme when the sequence of the calculated curvatures match the sequence of the reference curvatures and coordinates of the extrema points corresponding to the sequence of the calculated curvatures match a set of the reference coordinates.

3 . The computer readable storage medium of claim 2 , wherein the reference curvatures of phonemes and the reference coordinates of the phonemes are stored in the device.

4 . The computer readable storage medium of claim 2 , wherein the reference curvatures of phonemes and the reference coordinates of the phonemes are stored in a remote system accessible over a network.

5 . The computer readable storage medium of claim 2 , wherein the phoneme function is a function representing air pressure over time.

6 . The computer readable storage medium of claim 5 , wherein the value of the phoneme function is the larger of:

absolute value of maximum value of the phoneme function; and

absolute value of minimum value of the phoneme function.

7 . The computer readable storage medium claim 1 , wherein the base frequency for the speech signal is determined in response to a voice input received at the computing device.

8 . A computer-implemented method for phoneme identification, the method comprising:

at a computing device, determining base frequency for a speech signal;

calculating curvatures at extrema points based on a normalized phoneme function, wherein the normalized phoneme function is a function of a time period of a phoneme function and a value of the phoneme function;

comparing the calculated curvatures with reference curvatures of phonemes;

when a sequence of the calculated curvatures matches a sequence of the reference curvatures, identifying a corresponding phoneme.

9 . The method of claim 8 , further comprising:

dividing the speech signal into frames; and

comparing coordinates of the extrema points with reference coordinates of the phonemes; and

identifying the corresponding phoneme, comprising:

identifying the corresponding phoneme when the sequence of the calculated curvatures match the sequence of the reference curvatures and coordinates of the extrema points corresponding to the sequence of the calculated curvatures match a set of the reference coordinates.

10 . The method of claim 9 , wherein the reference curvatures of phonemes and he reference coordinates of the phonemes are stored in the device.

11 . The method of claim 9 , wherein the reference curvatures of phonemes and the reference coordinates of the phonemes are stored in a remote system accessible over a network.

12 . The method of claim 9 , wherein the phoneme function is a function representing air pressure over time.

13 . The method of claim 12 , wherein the value of the phoneme function is the larger of:

absolute value of maximum value of the phoneme function; and

absolute value of minimum value of the phoneme function.

14 . The method of claim 8 , wherein the base frequency for the speech signal is determined in response to a voice input received at the computing device.

15 . A computer system for phoneme identification, comprising:

a memory to store program code; and

a processor to execute the program code to perform operations comprising:

determining base frequency for a speech signal;

calculating curvatures at extrema points based on a normalized phoneme function, wherein the normalized phoneme function is a function of a time period of a phoneme function and a value of the phoneme function;

comparing the calculated curvatures with reference curvatures of phonemes;

when a sequence of the calculated curvatures matches a sequence of the reference curvatures, identifying a corresponding phoneme.

16 . The system of claim 15 , wherein the processor further executes the program code to perform operations further comprising:

dividing the speech signal into frames; and

comparing coordinates of the extrema points with reference coordinates of the phonemes; and

identifying the corresponding phoneme, comprising:

identifying the corresponding phoneme when the sequence of the calculated curvatures match the sequence of the reference curvatures and coordinates of the extrema points corresponding to the sequence of the calculated curvatures match a set of the reference coordinates.

17 . The system of claim 16 , wherein the reference curvatures of phonemes and the reference coordinates of the phonemes are stored in the computer system.

18 . The system of claim 16 , wherein the reference curvatures of phonemes and the reference coordinates of the phonemes are stored in a remote system accessible over a network.

19 . The system of claim 16 , wherein the phoneme function is a function representing air pressure over time and the base frequency for the speech signal is determined in response to a voice input received at a computing device.

20 . The system of claim 19 , wherein the value of the phoneme function is the larger of:

absolute value of maximum value of the phoneme function; and

absolute value of minimum value of the phoneme function