Waveform processing device, waveform processing method, and waveform processing program

Patent metadata

Field	Value
Publication number	US-9443538-B2
Application number	US-201214131460-A
Country	US
Kind code	B2
Filing date	Jun 26, 2012
Priority date	Jul 19, 2011
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

There is provided a waveform processing device for changing power of each pitch waveform of a segment in order to acquire a natural synthesis speech. A power calculation means 71 selects pitch waveforms one by one from a group of pitch waveforms corresponding to a segment, and calculates a scalar indicating power of a selected pitch waveform. A normalization degree calculation means 72 calculates a degree of normalization which is an index indicating a degree of normalization of a pitch waveform selected by the power calculation means 71 , as a function value of an increasing function using the scalar as a variable. A change coefficient calculation means 73 calculates a change coefficient for changing an amplitude value of a pitch waveform selected by the power calculation means 71 based on the scalar and the degree of normalization. An amplitude change means 74 multiplies an amplitude value at each sampling point of a pitch waveform selected by the power calculation means 71 by the change coefficient.

First claim

The invention claimed is:

1. A waveform processing device comprising:
a processor; and
an interface coupled to the processor;
wherein the processor is configured to:
select pitch waveforms one by one from a group of pitch waveforms corresponding to a segment of a speech to be processed as synthesis speech;

calculate a scalar indicating power of a selected pitch waveform;
calculate a degree of normalization which is an index indicating a degree of normalization of a pitch waveform, as a function value of an increasing function using the scalar as a variable;
calculate a change coefficient for changing an amplitude value of the selected pitch waveform based on the scalar and the degree of normalization, wherein assuming a change coefficient g, a predefined constant C, a scalar S, and a degree of normalization α, calculate the change coefficient g meeting (C/S)≦g≦1.0 as a function value of a function using the variables S and α; and
change an amplitude at each sampling point of the selected pitch waveform based on the change coefficient g to produce a modified pitch waveform,

wherein using the change coefficient g for changing the amplitude of the selected pitch waveform to produce the modified pitch waveform reduces unbalanced power in the modified pitch waveform.

2. The waveform processing device according to claim 1 , wherein the processor is further configured to
generate a waveform indicating a segment by coupling pitch waveforms.

3. The waveform processing device according to claim 2 , wherein the processor is further configured to
couple waveforms indicating a segment.

4. The waveform processing device according to claim 1 , wherein the processor is further configured to
store a group of pitch waveforms corresponding to a segment per segment.

5. The waveform processing device according to claim 1 , wherein the processor is further configured to:
store waveforms of a recorded speech;
cut out a waveform of the recorded speech per segment; and
cut out a waveform cut out per segment per pitch waveform; and
generate a group of pitch waveforms corresponding to a segment per segment.

6. A waveform processing method implemented in a processor having an interface coupled to the processor, the method comprising the steps of:
selecting pitch waveforms one by one from a group of pitch waveforms corresponding to a segment of a speech to be processed as synthesis speech and calculating a scalar indicating power of a selected pitch waveform;
calculating a degree of normalization which is an index indicating a degree of normalization of a selected pitch waveform, as a function value of an increasing function using the scalar as a variable;
calculating a change coefficient for changing an amplitude value of the selected pitch waveform based on the scalar and the degree of normalization, wherein assuming a change coefficient g, a predefined constant C, a scalar S, and a degree of normalization α, calculating the change coefficient g meeting (C/S)≦g≦1.0 as a function value of a function using the variables S and α; and
changing an amplitude value at each sampling point of the selected pitch waveform based on the change coefficient g to produce a modified pitch waveform,

wherein using the change coefficient g for changing the amplitude of the selected pitch waveform to produce the modified pitch waveform reduces unbalanced power in the modified pitch waveform.

7. A non-transitory computer-readable recording medium coupled to a processor having an interface coupled to the processor in which a waveform processing program is recorded, the waveform processing program causing a computer to perform:
a power calculating processing of selecting pitch waveforms one by one from a group of pitch waveforms corresponding to a segment of a speech to be processed as synthesis speech, and calculating a scalar indicating power of a selected pitch waveform;
a normalization degree calculation processing of calculating a degree of normalization which is an index indicating a degree of normalization of a pitch waveform selected in the power calculation processing, as a function value of an increasing function using the scalar as a variable;
a change coefficient calculation processing of calculating a change coefficient for changing an amplitude value of the selected pitch waveform selected in the power calculation processing based on the scalar and the degree of normalization, wherein the waveform processing program causing a computer to,
assuming a change coefficient g, a predefined constant C, a scalar S calculated in the power calculation processing, and a degree of normalization α, calculate the change coefficient g meeting (C/S)≦g≦1.0 as a function value of a function using the variables S and α; and
an amplitude change processing of changing an amplitude value at each sampling point of the selected pitch waveform selected in the power calculation processing by the change coefficient g to produce a modified pitch waveform,

wherein using the change coefficient g for changing the amplitude of the selected pitch waveform to produce the modified pitch waveform reduces unbalanced power in the modified pitch waveform.

Assignees

• Kato Masanori
• Kondo Reishi
• Mitsui Yasuyuki
• Nec Corp

Inventors

• Kato Masanori
• Kondo Reishi
• Mitsui Yasuyuki

Classifications

• G10L13/06

  Elementary speech units used in speech synthesisers; Concatenation rules · CPC title

• G10L25/90 Primary

  Pitch determination of speech signals · CPC title

• G10L13/07

  Concatenation rules · CPC title

• G10L13/033 Primary

  Voice editing, e.g. manipulating the voice of the synthesiser · CPC title