Voice Synthesis Apparatus

• US 20120310651A1
• Filed: 05/31/2012
• Published: 12/06/2012
• Est. Priority Date: 06/01/2011
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: SAINO, Keijiro
• Granted Patent: US 9,230,537 B2
• Time in Patent Office: Days
• US Class Current: 704/267
• CPC Class Codes: G10L 13/033 Voice editing, e.g. manipulating the voice of the synthesiser
• CPC Class Codes: G10L 13/07 Concatenation rules
• CPC Class Codes: G10L 21/049 characterised by the interconnection of waveforms
• CPC Class Codes: G10L 25/93 Discriminating between voiced and unvoiced parts of speech signals G10L25/90 takes precedence

Abstract

A voice signal is synthesized using a plurality of phonetic piece data each indicating a phonetic piece containing at least two phoneme sections corresponding to different phonemes. In the apparatus, a phonetic piece adjustor forms a target section from first and second phonetic pieces so as to connect the first and second phonetic pieces to each other such that the target section includes a rear phoneme section of the first piece and a front phoneme section of the second piece, and expands the target section by a target time length to form an adjustment section such that a central part is expanded at an expansion rate higher than that of front and rear parts of the target section, to thereby create synthesized phonetic piece data having the target time length. A voice synthesizer creates a voice signal from the synthesized phonetic piece data.

Claims

1. An apparatus for synthesizing a voice signal using a plurality of phonetic piece data each indicating a phonetic piece which contains at least two phoneme sections corresponding to different phonemes, the apparatus comprising;

a phonetic piece adjustment part that forms a target section from a first phonetic piece and a second phonetic piece so as to connect the first phonetic piece and the second phonetic piece to each other such that the target section is formed of a rear phoneme section of the first phonetic piece corresponding to a consonant phoneme and a front phoneme section of the second phonetic piece corresponding to the consonant phoneme, and that carries out an expansion process for expanding the target section by a target time length to form an adjustment section such that a central part of the target section is expanded at an expansion rate higher than that of a front part and a rear part of the target section, to thereby create synthesized phonetic piece data of the adjustment section having the target time length and corresponding to the consonant phoneme; and

a voice synthesis part that creates a voice signal from the synthesized phonetic piece data created by the phonetic piece adjustment part.

2. The apparatus according to claim 1,

wherein each phonetic piece data comprises a plurality of unit data corresponding to a plurality of frames arranged on a time axis, and

wherein in case that the target section corresponds to a voiced consonant phoneme, the phonetic piece adjustment part expands the target section to the adjustment section such that the adjustment section contains a time series of unit data corresponding to the front part of the target section, a time series of a plurality of repeated unit data which are obtained by repeating unit data corresponding to a central point of the target section, and a time series of a plurality of unit data corresponding to the rear part of the target section.

3. The apparatus according to claim 2,

wherein the unit data of the frame of the voiced consonant phoneme comprises envelope data designating characteristics of a shape in an envelope line of a spectrum of a voice and spectrum data indicating the spectrum of the voice, and

wherein the phonetic piece adjustment part generates the unit data corresponding to the central point of the target section such that the generated unit data comprises envelope data obtained by interpolating the envelope data of the unit data before and after the central point of the target section and spectrum data of the unit data immediately before or after the central point.

4. The apparatus according to claim 1,

wherein the phonetic piece data comprises a plurality of unit data corresponding to a plurality of frames arranged on a time axis,

wherein in case that the target section corresponds to an unvoiced consonant phoneme, the phonetic piece adjustment part sequentially selects the unit data of each frame of the target section as unit data of each frame of the adjustment section to create the synthesized phonetic piece data, and

wherein velocity, at which each frame in the target section corresponding to each frame in the adjustment section is changed according to passage of time in the adjustment section, is decreased from a front part to a central point of the adjustment section and increased from the central point to a rear part of the adjustment section.

5. The apparatus according to claim 4,

wherein the unit data of the frame of an unvoiced sound comprises spectrum data indicating a spectrum of the unvoiced sound, and

wherein the phonetic piece adjustment part creates the unit data of the frame of the adjustment section such that the created unit data comprises spectrum data of a spectrum containing a predetermined noise component adjusted according to an envelope line of a spectrum indicated by spectrum data of unit data of a frame in the target section.

6. The apparatus according to claim 1, wherein the phonetic piece adjustment part carries out the expansion process in case that the consonant phoneme of the target section belongs to one type including fricative sound and semivowel sound, and carries out another expansion process in case that the consonant phoneme of the target section belongs to another type including plosive sound, affricate sound, nasal sound and liquid sound for inserting an intermediate section between the rear phoneme section of the first phonetic piece and the front phoneme section of the second phonetic piece in the target section.

7. The apparatus according to claim 6, wherein the phonetic piece adjustment part inserts a silence section as the intermediate section between the rear phoneme section of the first phonetic piece and the front phoneme section of the second phonetic piece in case that the consonant phoneme of the target section is plosive sound or affricate sound.

8. The apparatus according to claim 6, wherein the phonetic piece adjustment part inserts the intermediate section containing repetition of a frame selected from the rear phoneme section of the first phonetic piece or the front phoneme section of the second phonetic piece in case that the consonant phoneme of the target section is nasal sound or liquid sound.

9. The apparatus according to claim 8, wherein the phonetic piece adjustment part inserts the intermediate section containing repetition of the last frame of the rear phoneme section of the first phonetic piece.

10. The apparatus according to claim 8, wherein the phonetic piece adjustment part inserts the intermediate section containing repetition of the top frame of the front phoneme section of the second phonetic piece.

11. A machine readable storage medium containing a program executable by a computer to perform a method of synthesizing a voice signal using a plurality of phonetic piece data each indicating a phonetic piece which contains at least two phoneme sections corresponding to different phonemes, the method comprising;

forming a target section from a first phonetic piece and a second phonetic piece so as to connect the first phonetic piece and the second phonetic piece to each other such that the target section is formed of a rear phoneme section of the first phonetic piece corresponding to a consonant phoneme and a front phoneme section of the second phonetic piece corresponding to the consonant phoneme;

carrying out an expansion process for expanding the target section by a target time length to form an adjustment section such that a central part of the target section is expanded at an expansion rate higher than that of a front part and a rear part of the target section, to thereby create synthesized phonetic piece data of the adjustment section having the target time length and corresponding to the consonant phoneme; and

creating a voice signal from the synthesized phonetic piece.