Gain adjusting method and a gain adjusting device

• US 20070223716A1
• Filed: 06/07/2006
• Published: 09/27/2007
• Est. Priority Date: 03/09/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Tsuchinaga, Yoshiteru, Makiuchi, Takashi, Shirakawa, Miyuki, Suzuki, Masanao
• Granted Patent: US 7,916,874 B2
• Time in Patent Office: Days
• US Class Current: 381/73.100
• CPC Class Codes: G10L 19/26 Pre-filtering or post-filtering
• CPC Class Codes: G10L 21/0232 Processing in the frequency domain
• CPC Class Codes: G10L 21/0364 for improving intelligibility
• CPC Class Codes: H03G 5/005 of digital signals
• CPC Class Codes: H03G 5/165 Equalizers; Volume or gain control in limited frequency bands

Abstract

A gain adjusting method and a gain adjusting device for adjusting gain of a processed voice signal that is obtained by signal processing an input voice signal are disclosed. According to the gain adjusting method,

a masking property of the processed voice signal is computed, and

gain is adjusted for every frequency if the frequency is masked according to the masking property, while canceling a difference between the processed voice signal and the input voice signal where the frequency is not masked.

Claims

1. A gain adjusting method of adjusting gain of a processed voice signal obtained by carrying out signal processing on an input voice signal, the processed voice signal being output to a next stage, comprising:

a step of computing a masking property of the processed voice signal; and

a step of adjusting gain for each frequency of the processed voice signal, the frequency being masked according to the masking property, while a difference between the processed voice signal and the input voice signal is cancelled for a frequency other than the frequency that is masked according to the masking property.

2. The gain adjusting method as claimed in claim 1, wherein

the input voice signal and the processed voice signal are in a frequency domain.

3. The gain adjusting method as claimed in claim 2, wherein

the step of adjusting the gain adjusts the gain for each frequency band.

4. The gain adjusting method as claimed in claim 2, wherein

the step of adjusting the gain adjusts the gain for each frequency spectrum.

5. A gain adjustment device for adjusting gain of a processed voice signal obtained by carrying out signal processing on an input voice signal, the processed voice signal being output to a next stage, comprising:

a masking property computing unit for computing a masking property of the processed voice signal; and

an adjusting unit for adjusting the gain for each frequency of the processed voice signal, the frequency being masked according to the masking property, while a difference between the processed voice signal and the input voice signal is cancelled for a frequency other than the frequency that is masked according to the masking property.

6. The gain adjusting device as claimed in claim 5, wherein

the input voice signal and the processed voice signal are in a frequency domain.

7. The gain adjusting method as claimed in claim 6, wherein

the gain adjusting unit adjusts the gain for each frequency band.

8. The gain adjusting method as claimed in claim 6, wherein

the gain adjusting unit adjusts the gain for each frequency spectrum.

9. A gain adjusting device, comprising:

a first orthogonal transformation unit for carrying out orthogonal transformation of an input voice signal in a time domain to an input voice signal in a frequency domain;

a second orthogonal transformation unit for carrying out orthogonal transformation of a processed voice signal, which processed voice signal is obtained by performing signal processing on the input voice signal in the time domain, to a processed voice signal in the frequency domain;

a masking property computing unit for computing a masking property of the processed voice signal in the frequency domain;

a frequency selecting unit for selecting a frequency that is masked according to the masking property out of the processed voice signal in the frequency domain;

a gain determining unit for determining gain for every frequency out of the frequencies selected by the frequency selecting unit, while a difference between the processed voice signal and the input voice signal is cancelled for a frequency other than the frequency that is masked according to the masking property;

a gain adjusting unit for adjusting the gain according to the gain determined by the gain determining unit for the frequency that is selected by the frequency selecting unit; and

a third orthogonal transformation unit for carrying out orthogonal transformation of the voice signal in the frequency domain, which voice signal is output by the gain adjusting unit, to the voice signal in the time domain, and for outputting the voice signal in the time domain.