Acoustic signal processing apparatus and method, and audio device
A first band analyzer divides an acoustic signal received from a sound playback system through an input unit into frequency bands, and generates a first band level. An acoustic signal estimator estimates the band level of the original acoustic signal at the input unit, and generates a second band level for each band. A processor extracts an external noise component which is contained in the acoustic signal using the first band level and the second band level. The external noise can be accurately estimated with less computation than in the related art.
1. An acoustic signal processing apparatus comprising:
an audio source for generating an audio signal;
an audio correction filter for receiving the audio signal and correcting the audio signal to contain a component for canceling an external noise component in a sound playback system;
a speaker for receiving the corrected audio signal and providing an acoustic signal to the sound playback system;
a first band analyzer for dividing an acoustic signal received from the sound playback system through an input unit into a plurality of frequency bands and for generating a first band level for each band;
an acoustic signal estimator for estimating the band level at the input unit of the acoustic signal provided by the speaker and for generating a second band level for each band; and
a processor for extracting the external noise component, which is contained in the acoustic signal received from the sound playback system through the input unit, using the first band level and the second band level;
wherein the audio correction filter multiplies the audio signal by an audio correction coefficient generated according to the external noise component extracted by the processor.
2. An acoustic signal processing apparatus according to claim 1 , wherein the acoustic signal estimator includes:
a second band analyzer for dividing an audio signal corresponding to the acoustic signal which has not been supplied to the sound playback system into the plurality of frequency bands and for generating a third band level; and
a calculator for correcting the third band level according to an acoustic characteristic of the sound playback system which is in the state where the sound playback system does not have the external noise component.
3. An acoustic signal processing apparatus according to claim 1 , wherein the acoustic signal estimator includes:
a second band analyzer for dividing an audio signal corresponding to the acoustic signal which has not been supplied to the sound playback system into the plurality of frequency bands and for generating a third band level; and
a calculator for multiplying the third band level by a coefficient according to an acoustic characteristic of the sound playback system.
4. An acoustic signal processing apparatus according to claim 3 , wherein the acoustic signal estimator further includes a coefficient adjusting unit for adjusting the value of the coefficient.
5. An acoustic signal processing apparatus according to claim 1 , wherein the acoustic signal estimator selectively generates a plurality of second band levels depending upon a state of the sound playback system.
6. An acoustic signal processing apparatus according to claim 1 , wherein the processor subtracts the second band level from the first band level.
7. An acoustic signal processing apparatus according to claim 1 , wherein the first band analyzer, the acoustic signal estimator, and the processor are formed on a single chip.
8. An acoustic signal processing apparatus according to claim 1 , wherein the band level comprises a mean level for each frequency band.
9. An audio signal processing method comprising:
receiving an audio signal;
correcting the audio signal to contain a component for canceling an external noise component in a sound playback system;
providing an acoustic signal to the sound playback system using the corrected audio signal;
dividing an acoustic signal received from the sound playback system through an input unit into a plurality of frequency bands and generating a first band level for each band;
estimating the band level at the input unit of the acoustic signal provided to the sound playback system and generating a second band level for each band; and
extracting the external noise component, which is contained in the acoustic signal received from the sound playback system through the input unit, using the first band level and the second band levels;
wherein the act of correcting includes multiplying the audio signal by an audio correction coefficient based on the extracted external noise component.
10. An audio signal processing method according to claim 9 , wherein the act of estimating the band level of the original acoustic signal at the input unit and generating a second band level for each band includes:
a second band analyzing act of dividing an audio signal corresponding to the acoustic signal which has not been supplied to the sound playback system into the plurality of frequency bands and generating a third band level; and
correcting the third band level according to an acoustic characteristic of the sound playback system which is in the state where the sound playback system does not have the external noise component.
11. An acoustic signal processing method according to claim 9 , wherein the act of estimating the band level of the acoustic signal at the input unit and generating a second band level for each band includes:
a second band analyzing act of dividing an audio signal corresponding to the acoustic signal which has not been supplied to the sound playback system into the plurality of frequency bands and outputting a third band level; and
multiplying the third band level by a coefficient according to an acoustic characteristic of the sound playback system.
12. An acoustic signal processing method according to claim 11 , wherein the act of estimating the band level of the acoustic signal at the input unit and generating a second band level for each band further includes an act of adjusting the value of the coefficient.
13. An acoustic signal processing apparatus according to claim 11 , wherein the act of estimating the band level of the acoustic signal at the input unit and generating a second band level for each band further includes an act of selectively generating a plurality of second band levels depending upon a state of the sound playback system.
14. An audio device comprising:
an audio source for generating an audio signal;
a correction unit for receiving the audio signal and correcting the audio signal to contain a component for canceling an external noise component in a sound playback system; and
a speaker for receiving the corrected audio signal and providing an acoustic signal to the sound playback system;
wherein the correction unit includes:
a first band analyzer for dividing an acoustic signal received from the sound playback system through an input unit into a plurality of frequency bands and for generating a first band level for each band;
an acoustic signal estimator for estimating the band level at the input unit of the acoustic signal provided by the speaker and for generating a second band level for each band;
a processor for extracting the external noise component, which is contained in the acoustic signal received from the sound playback system through the input unit, using the first band level and the second band level; and
a corrector for correcting the audio signal by multiplying the audio signal by an audio correction coefficient generated according to the external noise component extracted by the processor.
15. An audio device according to claim 14 , wherein the correction unit includes a filter for performing audio correction on the audio signal according to the external noise component.
16. An audio device according to claim 14 , wherein the acoustic signal estimator includes:
a second band analyzer for dividing an audio signal corresponding to the acoustic signal which has not been supplied to the sound playback system into the plurality of frequency bands and for generating a third band level; and
a calculator for correcting the third band level according to an acoustic characteristic of the sound playback system which is in the state where the sound playback system does not have the external noise component.
17. An audio device according to claim 14 , wherein the acoustic signal estimator includes:
a second band analyzer for dividing an audio signal corresponding to the acoustic signal which has not been supplied to the sound playback system into the plurality of frequency bands and for generating a third band level; and a calculator for multiplying the third band level by a coefficient according to an acoustic characteristic of the sound playback system.
18. An acoustic signal processing apparatus according to claim 17 , wherein the acoustic signal estimator further includes a coefficient adjusting unit for adjusting the value of the coefficient.
19. An acoustic signal processing apparatus according to claim 14 , wherein the acoustic signal estimator selectively generates a plurality of second band levels depending upon a state of the sound playback system.
20. An acoustic signal processing apparatus according to claim 14 , wherein the processor subtracts the second band level from the first band level.
21. An acoustic signal processing apparatus according to claim 14 , wherein the band level comprises a mean level for each frequency band.