Audio signal processing apparatus and method for the same

• US 20060067541A1
• Filed: 09/19/2005
• Published: 03/30/2006
• Est. Priority Date: 09/28/2004
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamada, Yuji, Okimoto, Koyuru
• Granted Patent: US 7,672,466 B2
• Time in Patent Office: Days
• US Class Current: 381/98
• CPC Class Codes: G10H 1/361 Recording/reproducing of accompaniment for use with an external source, e.g. karaoke systems
• CPC Class Codes: G10H 2210/046 for differentiation between music and non-music signals, based on the identification of musical parameters, e.g. based on tempo detection
• CPC Class Codes: G10L 21/0272 Voice signal separating
• CPC Class Codes: G10L 25/18 the extracted parameters being spectral information of each sub-band
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10

Abstract

An audio signal processing apparatus includes a splitting unit for splitting an audio signal of a first system and another audio signal of a second system into pluralities of frequency band components, a level comparing unit for calculating a level ratio or a level difference between each of the frequency bands of the first system and each of the frequency bands of the second systems, and an output control unit for removing frequency band components whose level ratio or level difference calculated by the level comparing unit is equal and substantially equal to a predetermined value from at least one of the first and second systems.

Claims

1. An audio signal processing apparatus comprising:

splitting means for splitting an audio signal of a first system and another audio signal of a second system into pluralities of frequency band components;

level comparing means for calculating a level ratio or a level difference between each of the frequency bands of the first system and each of the frequency bands of the second systems; and

output control means for removing frequency band components whose level ratio or level difference calculated by the level comparing means is equal and substantially equal to a predetermined value from at least one of the first and second systems.

2. An audio signal processing apparatus comprising:

first conversion means for converting time-sequential audio signals from a first system into frequency domain signals;

second conversion means for converting time-sequential audio signals from a second system into frequency domain signals;

level calculating means for calculating a level ratio or a level difference between frequency spectral components from the first conversion means and the frequency spectral components from the second conversion means, the frequency spectral components from the first conversion means and the frequency spectral components from the second conversion means corresponding to each other;

output control means for controlling the level of the frequency spectral components obtained from at least one of the first and second conversion means on the basis of the calculation result of the level calculating means and removing frequency spectral components whose level ratio or level difference calculated by the level comparing means is equal and substantially equal to a predetermined value from at least one of frequency spectral components of the first system and frequency spectral components of second system; and

inverse conversion means for converting the frequency domain signals from the output control means into time-sequential signals.

3. The audio signal processing apparatus according to claim 2, further comprising:

phase difference calculating means for calculating the phase difference between the frequency spectral components from the first conversion means and the frequency spectral components from the second conversion means, the frequency spectral components from the first conversion means and the frequency spectral components from the second conversion means corresponding to each other,

wherein the output control means controls the level of the frequency spectral components obtained from at least one of the first and second conversion means on the basis of the calculation result of the level calculating means and the phase difference calculated by the phase difference calculating means and removes the frequency spectral components whose phase difference is equal and substantially equal to a predetermined value from at least one of the frequency spectral components of the first system and frequency spectral components of second system.

4. The audio signal processing apparatus according to claim 2, wherein the output control means includes

a multiplication coefficient generating unit for generating a multiplication coefficient that is set as a function of the level ratio or the level difference calculated at the level calculating means, and

a multiplying unit for determining an output level of the frequency spectral components obtained from at least one of the first conversion means and the second conversion means by multiplying the multiplication coefficient generated at the multiplication coefficient generating unit and the frequency spectral components.

5. The audio signal processing apparatus according to claim 3, wherein the output control means includes

a multiplication coefficient generating unit for generating a multiplication coefficient set as a function of the phase difference calculated at the phase difference calculating means, and

a multiplying unit for determining an output level of frequency spectral components obtained from at least one of the first conversion means and the second conversion means by multiplying the multiplication coefficient generated at the multiplication coefficient generating unit and the frequency spectral components.

6. The audio signal processing apparatus according to claim 2,

wherein the output control means includes a plurality of multiplication coefficient generating units for generating multiplication coefficients that are set as functions of the level ratio or level difference calculated at the level calculating means and a plurality of multiplying units for determining an output level of frequency spectral components obtained from at least one of the first conversion means and the second conversion means by multiplying the multiplication coefficients generated at the multiplication coefficient generating units and the frequency spectral components, and

wherein the inverse conversion means includes a plurality of inverse conversion sections for converting the outputs from the plurality of multiplying units into time-sequential signals.

7. The audio signal processing apparatus according to claim 2, wherein the output control means includes

a plurality of multiplication coefficient generating units for generating multiplication coefficients that are set as functions of the level ratio or level difference calculated at the level calculating means,

a selecting unit for selecting one of the multiplication coefficients generated at the plurality of multiplication coefficient generating units, and

a multiplying unit for determining an output level of frequency spectral components obtained from at least one of the first conversion means and the second conversion means by multiplying the multiplication coefficient selected at the selecting unit and the frequency spectral components.

8. The audio signal processing apparatus according to claim 2, further comprising:

sectioning means for generating section data items by sectioning time-sequential signals of first and second systems into predetermined sections, overlapping parts of adjacent section data items, and supplying the section data items to the first and second conversion means; and

output means for windowing time-sequential signals output from the inverse conversion means corresponding to the section data items, adding each of the time-sequential signals corresponding to the same time, and outputting the added results.

9. The audio signal processing apparatus according to claim 2, further comprising:

sectioning means for generating section data items by sectioning time-sequential signals of first and second systems into predetermined sections, overlapping parts of adjacent section data items, windowing the section data items, and supplying the section data items to the first and second conversion means; and

output means for adding each time-sequential signal from the inverse conversion means corresponding to the same time and outputting the added results.

10. An audio signal processing method comprising the steps of:

splitting an audio signal of a first system and another audio signal of a second system into pluralities of frequency band components;

calculating a level ratio or a level difference between each of the frequency bands of the first system and each of the frequency bands of the second systems; and

removing frequency band components whose level ratio or level difference calculated in the calculating step is equal and substantially equal to a predetermined value from at least one of the first and second systems.

11. An audio signal processing method comprising the steps of:

obtaining frequency spectral components of first and second systems by converting time-sequential audio signals of the first and second systems into frequency domain signals;

calculating a level ratio or a level difference between the frequency spectral components of the first system and the frequency spectral components of the second system obtained in the obtaining step, the frequency spectral components of the first system and the frequency spectral components of the second system corresponding to each other;

controlling the level of at least one of the frequency spectral components of the first system and the frequency spectral components second system obtained in the obtaining step on the basis of the calculation result obtained in the calculating step and removing frequency spectral components whose level ratio or level difference calculated in the calculating step is equal and substantially equal to a predetermined value from at least one of the first and second systems; and

converting the frequency domain signals obtained in the controlling step into time-sequential signals.

12. The audio signal processing method according to claim 11, further comprising the step of:

phase difference calculating the phase difference between frequency spectral components obtained in obtaining step, the frequency spectral components of the first system and the frequency spectral components of the second system corresponding to each other,

wherein the controlling step includes a step of removing the frequency spectral components whose phase difference is equal and substantially equal to a predetermined value from at least one of the first and second system by controlling the level of the frequency spectral components of the first and second systems obtained in the obtaining step on the basis of the calculation result obtained in the calculating step and the phase difference calculated in the phase difference.

13. An audio signal processing apparatus comprising:

a splitting unit configured to split an audio signal of a first system and another audio signal of a second system into pluralities of frequency band components;

a level comparing unit configured to calculate a level ratio or a level difference between each of the frequency bands of the first system and each of the frequency bands of the second systems; and

an output control unit configured to remove frequency band components whose level ratio or level difference calculated by the level comparing unit is equal and substantially equal to a predetermined value from at least one of the first and second systems.

14. An audio signal processing apparatus comprising:

a first conversion unit configured to convert time-sequential audio signals from a first system into frequency domain signals;

a second conversion unit configured to convert time-sequential audio signals from a second system into frequency domain signals;

a level calculating unit configured to calculate a level ratio or a level difference between frequency spectral components from the first conversion unit and the frequency spectral components from the second conversion unit, the frequency spectral components from the first conversion unit and the frequency spectral components from the second conversion units corresponding to each other;

an output control unit configured to control the level of the frequency spectral components obtained from at least one of the first and second conversion units on the basis of the calculation result of the level calculating unit and removing frequency spectral components whose level ratio or level difference calculated by the level comparing unit is equal and substantially equal to a predetermined value from at least one of the first and second conversion units; and

an inverse conversion unit configured to convert the frequency domain signals from the output control unit into time-sequential signals.