Method of speaking rate conversion in text-to-speech system

• US 20060136215A1
• Filed: 11/30/2005
• Published: 06/22/2006
• Est. Priority Date: 12/21/2004
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Jong Jin
• Application Number:
  US11/290,908
• Publication Number:
  US 20060136215A1
• Time in Patent Office: Days
• US Class Current: 704/265
• CPC Class Codes: G10L 13/033 Voice editing, e.g. manipulating the voice of the synthesiser

Abstract

A method of a speaking rate conversion in a text-to-speech system is provided. The method includes: a first step of extracting a vocal list from a synthesis DB (database), voicing the extracted vocal list in each speaking style constituted of fast speaking, normal speaking, and slow speaking, and building a probability distribution of a synthesis unit-based duration; a second step of searching for an optimal synthesis unit candidate row using a viterbi search, correspondingly to a requested synthesis, and creating a target duration parameter of a synthesis unit; and a third step of again obtaining an optimal synthesis unit candidate row using the duration parameter of the optimal synthesis unit candidate row, and generating a synthesized sound.

Claims

1. A method of a speaking rate conversion in a text-to-speech system, the method comprising:

a first step of extracting a vocal list from a synthesis DB (database), voicing the extracted vocal list in each speaking style constituted of fast speaking, normal speaking, and slow speaking, and building a probability distribution of a synthesis unit-based duration;

a second step of searching for an optimal synthesis unit candidate row using a viterbi search, correspondingly to a requested synthesis, and creating a target duration parameter of a synthesis unit; and

a third step of again obtaining an optimal synthesis unit candidate row using the duration parameter of the optimal synthesis unit candidate row, and generating a synthesized sound.

2. The method of claim 1, wherein the first step comprises the steps of:

extracting an optimal training list for creating a synthesis unit-based duration training model, from the synthesis DB;

recording the extracted training list at the fast speaking and the slow speaking; and

obtaining a continuous probability distribution of a synthesis unit-based duration depending on a speaking rate, from a fast speaking training DB and a slowly speaking training DB.

3. The method of claim 1 or 2, wherein in the first step, the continuous probability distributions (PDP_slow(T_i), PDP_normal(T_i), and PDP_fast(T_i)) of the duration of the speaking style-based synthesis unit (T_i) are expressed using the following Equation 5:

PDP_slow(T_i)={μ

_slow(T_i), σ

_slow(T_i)}
PDP_normal(T_i)={μ

_normal(T_i), σ

_normal(T_i)}
PDP_fast(T_i)={μ

_fast(T_i), σ

_fast(T_i)}. 

 

[Equation 5]

4. The method of claim 3, wherein the normal speaking is obtained from an original synthesis DB.

5. The method of claim 1, wherein the third step comprises the steps of:

producing a new target duration parameter of a final synthesis unit finally influenced from the speaking rate, using a target duration and a continuous probability distribution of a duration of a synthesis unit candidate at the normal speaking, in duration models of synthesis units at the selected slow speaking or fast speaking;

again obtaining an optimal synthesis unit candidate row dependent on a duration, using a viterbi search of the produced new target duration parameter; and

generating a synthesized sound using the again obtained duration-dependent optimal synthesis unit candidate row.

6. The method of claim 5, wherein a process of converting to the new target duration parameter d′

(T′

_si) is expressed using the following Equation 8;

$\begin{array}{cc}{d<br><br>\left(t\right)}^{\mathrm{\prime <br><br>}}={\mathrm{\mu <br><br>}}_{\mathrm{target}}<br><br>\left(t\right)+\frac{\left(d<br><br>\left(t\right)-{\mathrm{\mu <br><br>}}_{\mathrm{normal}}<br><br>\left(t\right)\right)·<br><br>{\mathrm{\sigma <br><br>}}_{\mathrm{target}}<br><br>\left(t\right)·<br><br>U_{\mathrm{st}}}{{\mathrm{\sigma <br><br>}}_{\mathrm{normal}}<br><br>\left(t\right)}& \left[\mathrm{Equation}<br><br>\text{\hspace{1em}<br><br>}<br><br>8\right]\end{array}$

where

U_SR;

rate of speaking rate conversion requested by user,

t;

T′

_si.