Method and apparatus to simulate 2-channel virtualized sound for multi-channel sound

1. A stereo sound generation method of generating a 2-channel stereo sound from a 5.1-channel sound signal, the method comprising:

generating a first channel stereo signal and a second channel stereo signal, by applying a difference between times taken to arrive at two ears of a listener, respectively, and a difference between sound pressures of the two ears that are different or constant in frequency to each of a first channel signal and a second channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency to each of a third channel signal and a fourth channel signal being input;

generating a first channel signal and a second channel signal from each of a fifth channel signal and a sixth channel signal being input;

generating a plurality of reflected sounds by applying delay values and gain values different from each other to first through fifth channel signals being input, and from the plurality of generated reflected sounds, generating a first channel signal and a second channel signal; and

adding the generated first channel signals and adding the generated second channel signals,

wherein at least one of the generating steps and the adding step are performed by a controller to generate the 2-channel stereo sound.

2. The method of claim 1 , further comprising multiplying the input channel signals by predetermined gain values different from each other, respectively.

3. The method of claim 1 , further comprising low-pass filtering the plurality of generated reflected sounds.

4. The method of claim 1 , wherein the generating of the plurality of reflected sounds comprises:

multiplying the first through fifth channel signals by gain values different from each other, respectively;

generating reflected sounds by applying delay values different from each other to the multiplied channel signals, respectively;

adding the generated reflected sounds; and

continuously generating reflected sounds by passing the added reflected sounds through a plurality of all-pass filters that have delay coefficients different from each other and gain values different from each other, and are connected in series.

5. The method of claim 4 , wherein the different delay values are determined with respect to a size of a virtual space.

6. The method of claim 4 , wherein the different gain values are determined with respect to a degree of absorbing sound in a virtual space.

7. The method of claim 4 , wherein the delay values and gain values of the all-pass filters are determined with respect to a size of a virtual space and a degree of absorbing sound in the virtual space.

8. A stereo sound generation method of generating a 2-channel stereo sound from a 6.1-channel sound signal, the method comprising:

generating a first channel stereo signal and a second channel stereo signal, by applying a difference between times taken to arrive at two ears of a listener, respectively, and a difference between sound pressures of the two ears that are different or constant in frequency to each of a first channel signal and a second channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency to each of a third channel signal and a fourth channel signal being input;

generating a first channel signal and a second channel signal from each of fifth through seventh channel signals being input;

generating a plurality of reflected sounds by applying delay values and gain values different from each other to first through sixth channel signals being input, and from the plurality of generated reflected sounds, generating a first channel signal and a second channel signal; and

adding the generated first channel signals and adding the generated second channel signals,

wherein at least one of the generating steps and the adding step are performed by a controller to generate the 2-channel stereo sound.

9. The method of claim 8 , further comprising low-pass filtering the plurality of generated reflected sounds.

10. The method of claim 8 , wherein the generating of the plurality of reflected sounds comprises:

multiplying the first through sixth channel signals by gain values different from each other, respectively;

generating reflected sounds by applying delay values different from each other to the multiplied channel signals, respectively;

adding the generated reflected sounds; and

continuously generating reflected sounds by passing the added reflected sounds through a plurality of all-pass filters that have delay coefficients different from each other and gain values different from each other, and are connected in series.

11. A stereo sound generation method of generating a 2-channel stereo sound from a 7.1-channel sound signal, the method comprising:

generating a first channel stereo signal and a second channel stereo signal, by applying a difference between times taken to arrive at two ears of a listener, respectively, and a difference between sound pressures of the two ears that are different or constant in frequency to each of a first channel signal and a second channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency to each of a third channel signal and a fourth channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the different between the sound pressures of the two ears that are different or constant in frequency to each of a fifth channel signal and a sixth channel signal being input;

generating a first channel signal and a second channel signal from each of a seventh channel signal and an eighth channel signal being input;

generating a plurality of reflected sounds, by applying delay values and gain values different from each other to first through seventh channel signals being input, and from the plurality of generated reflected sounds, generating a first channel signal and a second channel signal; and

adding the generated first channel signals and adding the generated second channel signals,

wherein at least one of the generating steps and the adding step are performed by a controller to generate the 2-channel stereo sound.

12. The method of claim 11 , further comprising low-pass filtering the plurality of generated reflected sounds.

13. The method of claim 11 , wherein the generating of the plurality of reflected sounds comprises:

multiplying the first through seventh channel signals by gain values different from each other, respectively;

generating reflected sounds by applying delay values different from each other, to the multiplied channel signals, respectively;

adding the generated reflected sounds; and

continuously generating reflected sounds by passing the added reflected sounds through a plurality of all-pass filters that have delay coefficients different from each other and gain values different from each other, and are connected in series.

14. A non-transitory recording medium containing a method of generating a 2-channel stereo sound from a 5.1-channel sound signal, the method comprising:

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency, to each of a first channel signal and a second channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency, to each of a third channel signal and a fourth channel signal being input;

generating a first channel signal and a second channel signal from each of a fifth channel signal and a sixth channel signal being input;

generating a plurality of reflected sounds, by applying delay values and gain values different to each other to first through fifth channel signals being input, and from the plurality of generated reflected sounds, generating a first channel signal and a second channel signal; and

adding the generated first channel signals and adding the generated second channel signals.

15. A non-transitory recording medium containing a method of generating a 2-channel stereo sound from a 6.1-channel sound signal, the method comprising:

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency, to each of a first channel signal and a second channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency, to each of a third channel signal and a fourth channel signal being input;

generating a first channel signal and a second channel signal from each of fifth through seventh channel signals being input;

generating a plurality of reflected sounds, by applying delay values and gain values different to each other to first through sixth channel signals being input, and from the plurality of generated reflected sounds, generating a first channel signal and a second channel signal; and

adding the generated first channel signals and adding the generated second channel signals.

16. A non-transitory recording medium containing a method of generating a 2-channel stereo sound from a 7.1-channel sound signal, the method comprising:

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency, to each of a first channel signal and a second channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the difference between the sound pressures of the two ears that are different or constant in frequency, to each of a third channel signal and a fourth channel signal being input;

generating a first channel stereo signal and a second channel stereo signal, by applying the difference between times taken to arrive at the two ears, respectively, and the different between the sound pressures of the two ears that are different or constant in frequency, to each of fifth channel signal and a sixth channel signal being input;

generating a first channel signal and a second channel signal from each of a seventh channel signal and an eighth channel signal being input;

generating a plurality of reflected sounds, by applying delay values and gain values different to each other to first through seventh channel signals being input, and from the plurality of generated reflected sounds, generating a first channel signal and a second channel signal; and

adding the generated first channel signals and adding the generated second channel signals.