Speech synthesizing apparatus and method
First Claim
1. A speech synthesizing apparatus, comprising:
- division means for providing results by dividing a difference between present and target values for each of an adjacent two speech parameters of a synthesized voice by a predetermined number of subframe periods which together constitute a frame period, said present values being indicative respectively of values of each of said adjacent speech parameters at a beginning of the frame period, the target values being indicative respectively of values of each of said adjacent speech parameters at an end of the frame period;
means for determining interpolation pitches of said adjacent speech parameters based upon said results; and
means for interpolating the adjacent speech parameters during each of said subframe periods based on the interpolation pitches to produce interpolated speech parameters, said determining means determining said interpolation pitches so that whichever one of said adjacent speech parameters is greater than the other at said beginning of said frame period remains greater than the other at said end of said frame period; and
a synthesizing filter responsive to said interpolating means for filtering said interpolated speech parameters, said filter being thereby free of oscillation which would otherwise arise if said interpolation means, based on said interpolation pitches, caused whichever one of said adjacent speech parameters that was greater than the other at said beginning of said frame period to become less than the other at said end of said frame period.
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Accused Products
Abstract
A speech synthesizing apparatus includes an interpolation pitch calculation circuit wherein an interpolation pitch is calculated at every frame periods based upon a speech parameter. Specifically, a difference between a target value and a present value is stored in a shift register of 16 bits, and then, in order to omit the figures below the first place of decimals and to divide the difference by the number of subframes, the shift register is shifted rightward by 7 bits. If a numeral value of the shift register is negative, "1" is added to the number of units of the numeral value in an adding circuit such that an absolute value of the numeral value becomes smaller. When the numeral value of the shift register is positive, the numeral value outputted from the shift register is set in an interpolation pitch register as it is and, when negative, an output of the adding circuit is set in the interpolation pitch register.
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Citations
14 Claims
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1. A speech synthesizing apparatus, comprising:
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division means for providing results by dividing a difference between present and target values for each of an adjacent two speech parameters of a synthesized voice by a predetermined number of subframe periods which together constitute a frame period, said present values being indicative respectively of values of each of said adjacent speech parameters at a beginning of the frame period, the target values being indicative respectively of values of each of said adjacent speech parameters at an end of the frame period; means for determining interpolation pitches of said adjacent speech parameters based upon said results; and means for interpolating the adjacent speech parameters during each of said subframe periods based on the interpolation pitches to produce interpolated speech parameters, said determining means determining said interpolation pitches so that whichever one of said adjacent speech parameters is greater than the other at said beginning of said frame period remains greater than the other at said end of said frame period; and a synthesizing filter responsive to said interpolating means for filtering said interpolated speech parameters, said filter being thereby free of oscillation which would otherwise arise if said interpolation means, based on said interpolation pitches, caused whichever one of said adjacent speech parameters that was greater than the other at said beginning of said frame period to become less than the other at said end of said frame period. - View Dependent Claims (7, 8)
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9. A method of speech synthesizing, comprising the steps of:
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(a) providing results by dividing a difference between present and target values for each of an adjacent two speech parameters of a synthesized voice by a predetermined number of subframe periods which together constitute a frame period, said present values being indicative respectively of values of each of said adjacent speech parameters at a beginning of the frame period, the target values being indicative respectively of values of each of said adjacent speech parameters at an end of the frame period; (b) determining interpolation pitches of said adjacent speech parameters based upon said results; (c) interpolating the adjacent speech parameters during each of said subframe periods based on the interpolation pitches to produce interpolated speech parameters, the interpolation pitches being determined during the step of determining so that whichever one of the adjacent speech parameters is greater than the other at the beginning of the frame period remains greater than the other at the end of the frame period after the step of interpolating is effected; and (d) filtering said interpolated speech parameters, the filtering being thereby free of oscillation which would otherwise arise if the step of interpolating based on the interpolation pitches caused whichever one of said adjacent speech parameters that was greater than the other at said beginning of said frame period to become less than the other at said end of said frame period. - View Dependent Claims (2, 3, 4, 5, 6, 10, 11, 12, 13, 14)
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Specification