Voice signal processing apparatus and voice signal processing method

Patent metadata

Field	Value
Publication number	US-9699570-B2
Application number	US-201514804355-A
Country	US
Kind code	B2
Filing date	Jul 21, 2015
Priority date	Jun 5, 2015
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A voice signal processing apparatus and a voice signal processing method are provided. A last sampling point of an m th original frequency-lowered signal frame is determined according to a phase reference sampling point number of the m th original frequency-lowered signal frame. Here, the phase reference sampling point number corresponds to a middle sampling point of an m th renovating frequency-lowered signal frame, and the last sampling point is phase-matched with a sampling point corresponding to the phase reference sampling point number in the m th original frequency-lowered signal frame. P consecutive sampling points starting from the last sampling point are applied as sampling points of an (m+1) th renovating frequency-lowered signal frame.

First claim

What is claimed is:

1. A voice signal processing apparatus comprising:
a sampling circuit configured to sample an original voice signal to generate a sampling voice signal;
a processor coupled to the sampling circuit and configured to:
lower a frequency of the sampling voice signal to generate a frequency-lowered signal including a sequence of original frequency-lowered signal frames, wherein each of the original frequency-lowered signal frames comprises p sampling points;
adjust the sampling points of the original frequency-lowered signal frames to obtain renovating frequency-lowered signal frames; and
mix and stack adjacent renovating frequency-lowered signal frames of the renovating frequency-lowered signal frames to generate and output an overlapping voice signal,
wherein the processor determines a last sampling point of an m th original frequency-lowered signal frame of the original frequency-lowered signal frames phase-matched with the sampling point corresponding to a phase reference sampling point number according to the phase reference sampling point number of the m th original frequency-lowered signal frame corresponding to a middle sampling point of an m th renovating frequency-lowered signal frame of the renovating frequency-lowered signal frames,
wherein the processor sets p consecutive sampling points starting from the last sampling point phase-matched with the sampling point corresponding to the phase reference sampling point number as the sampling points of an (m+1) th renovating frequency-lowered signal frame of the renovating frequency-lowered signal frames,
and wherein the phase reference sampling point number is a serial number of the sampling point of the m th original frequency-lowered signal frame corresponding to the middle sampling point of the m th renovating frequency-lowered signal frame, p is a positive integer, and m is a positive integer greater than 1.

2. The voice signal processing apparatus of claim 1 , wherein each of two adjacent renovating frequency-lowered signal frames of the renovating frequency-lowered signal frames comprises a 50% overlapping section.

3. The voice signal processing apparatus of claim 2 , wherein the processor further adds up a first count value and a second count value according to sampling values of the sampling points of the m th original frequency-lowered signal frame, when the frequency-lowered signal in a positive half cycle is changed to a negative half cycle, the processor returns the first count value to 0, when the frequency-lowered signal in the negative half cycle is changed to the positive half cycle, the processor returns the second count value to 0, the processor sets the first count value or the second count value corresponding to the sampling point of the m th original frequency-lowered signal frame corresponding to the phase reference sampling point number as a reference value, and the processor determines the last sampling point of the m th original frequency-lowered signal frame phase-matched with the sampling point corresponding to the phase reference sampling point number according to the reference value.

4. The voice signal processing apparatus of claim 3 , wherein the processor further determines whether the first count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number is less than or equal to the second count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number,
if the first count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number is less than or equal to the second count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number, the processor sets the first count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number as the reference value and sets a last-sampled sampling point of the sampling points of the m th original frequency-lowered signal frame where the first count value is equal to the reference value as the last sampling point of the m th original frequency-lowered signal frame phase-matched with the sampling point corresponding to the phase reference sampling point number,
if the first count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number is greater than the second count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number, the processor sets the second count value of the m th original frequency-lowered signal frame corresponding to the sampling point corresponding to the phase reference sampling point number as the reference value and sets the last-sampled sampling point of the sampling points of the m th original frequency-lowered signal frame where the second count value is equal to the reference value as the last sampling point of the m th original frequency-lowered signal frame phase-matched with the sampling point corresponding to the phase reference sampling point number.

5. The voice signal processing apparatus of claim 1 , wherein the processor further multiplies the frequency-lowered signal by a Hamming window.

6. A voice signal processing method, applicable to a voice signal processing apparatus having a sampling circuit and a processor, comprising the following steps:
sampling an original voice signal by the sampling circuit to generate a sampling voice signal;
lowering a frequency of the sampling voice signal by the processor to generate a frequency-lowered signal including a sequence of original frequency-lowered signal frames, wherein each of the original frequency-lowered signal frames comprises p sampling points, and p is a positive integer;
adjusting the sampling points of the original frequency-lowered signal frames by the processor to obtain renovating frequency-lowered signal frames comprising:
determining a last sampling point of an m th original frequency-lowered signal frame of the original frequency-lowered signal frames by the processor according to a phase reference sampling point number of the m th original frequency-lowered signal frame, the phase reference sampling point number corresponding to a middle sampling point of an m th renovating frequency-lowered signal frame of the renovating frequency-lowered signal frames, the last sampling point being phase-matched with a sampling point corresponding to the phase reference sampling point number in the m th original frequency-lowered signal frame, wherein the phase reference sampling point number is a serial number of the sampling point of the m th original frequency-lowered signal frame corresponding to the middle sampling point of the m th renovating frequency-lowered signal frame, and m is a positive integer greater than 1; and

setting p consecutive sampling points starting from the last sampling point phase-matched with the sampling point corresponding to the phase reference sampling point number as the sampling points of an (m+1) th renovating frequency-lowered signal frame of the renovating frequency-lowered signal frames by the processor; and
mixing and stacking adjacent renovating frequency-lowered signal frames of the renovating frequency-lowered signal frames by the processor to generate and output an overlapping voice signal.

7. The voice signal processing method of claim 6 , wh

Assignees

• Acer Inc

Inventors

• Tu Po-Jen
• Chang Jia-Ren
• Tzeng Kai-Meng

Classifications

• H04R2225/43

  Signal processing in hearing aids to enhance the speech intelligibility · CPC title

• H04R25/353 Primary

  Frequency, e.g. frequency shift or compression · CPC title

• G10L21/0364

  for improving intelligibility · CPC title

• G10L21/057

  for improving intelligibility · CPC title

• G10L21/0202

  Physics · mapped topic