SYSTEM FOR MODIFYING AN ACOUSTIC SPACE WITH AUDIO SOURCE CONTENT

• US 20120275613A1
• Filed: 07/09/2012
• Published: 11/01/2012
• Est. Priority Date: 09/20/2006
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Inventors: Soulodre, Gilbert Arthur Joseph
• Granted Patent: US 9,264,834 B2
• Time in Patent Office: Days
• US Class Current: 381/63
• CPC Class Codes: G01H 7/00 Measuring reverberation time ; room acoustic measurements
• CPC Class Codes: G10L 2021/02082 the noise being echo, reverberation of the speech
• CPC Class Codes: H04R 29/00 Monitoring arrangements; Testing arrangements for hearing aids H04R25/30; detection of loudspeaker connection H04R5/04; sound-field adaptation dependent on speaker detection H04S7/308
• CPC Class Codes: H04S 5/005 of the pseudo five- or more-channel type, e.g. virtual surround
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone
• CPC Class Codes: H04S 7/305 Electronic adaptation of stereophonic audio signals to reverberation of the listening space H04S7/301 takes precedence

Abstract

An audio signal processing system is configured to separate an audio signal into a dry signal component and one or more reverberant signal components. The dry signal component and the reverberant signal components can be separately modified and then recombined to form a processed audio signal. Alternatively, the dry signal component may be combined with an artificial reverberation component to form the processed audio signal. Modification of the reverberation signal component and generation of the artificial reverberation component may be performed in order to modify the acoustic characteristics of an acoustic space in which the audio signal is driving loudspeakers. The audio signal may be a pre-recorded audio signal or a live audio signal generated inside or outside the acoustic space.

Claims

1. An audio signal processing system for modifying an acoustic space with audio source content, the audio signal processing system comprising:

a processor;

a memory in communication with the processor;

the memory configured to store a plurality of modules executable by the processor, the modules comprising;

a reverberation generator module configured to adjust an early reflection of an audio signal to modify a user perceived height of a ceiling of a listening space;

a signal modification module configured to create a multi-channel output signal based on the adjusted audio signal, the multichannel output signal comprising a first channel output signal configured to drive a first loudspeaker positioned in a listening space above a listener, and a second channel output signal configured to drive a second loudspeaker positioned in the listening space below an elevation of a listener'"'"'s ears.

2. The audio signal processing system of claim 1, where the early reflection is a plurality of early reflections, and the reverberation generation module is configured to separately adjust levels of the plurality of early reflections of the first channel output to modify the user perceived height of the ceiling of the listening space.

3. The audio signal processing system of claim 2, where the reverberation generation module is configured to separately adjust delays of the plurality of early reflections of the first channel output to modify the user perceived height of the ceiling of the listening space.

4. The audio signal processing system of claim 1, where the reverberation generation module is configured to separately adjust levels and delays of the plurality of early reflections of the second channel output to modify a user perceived height of a sound source above a floor of the listening space.

5. The audio signal processing system of claim 1, where the first channel output signal includes a dry signal component and a reverberation signal component, and the delay and level of the early reflection of the reverberation component are adjusted.

6. The audio signal processing system of claim 1, where the audio signal includes a dry signal component and a reverberation signal component, and the delay of the early reflection is adjusted in an estimate of the reverberation component, which is then combined with an estimate of the dry signal component.

7. The audio signal processing system of claim 6, where the adjusted estimate of the reverberation component is provided on at least one of the first channel output signal or the second channel output signal.

8. A method of modifying an acoustic space with audio source content, comprising:

processing an audio input signal, the audio input signal including a dry component and a reverberant component;

adjusting a level and a delay of an early reflection of only the reverberant component of the audio input signal to modify a listener perceived height of a ceiling of a listening space; and

outputting an adjusted audio output signal to drive a loudspeaker positioned above a listening position in the listening space, the adjusted audio output signal including at least a portion of the adjusted reverberant component and the dry component.

9. The method of claim 8, where the loudspeaker is a first loudspeaker, and the method further comprises outputting the adjusted audio input signal to also drive a second loudspeaker positioned below an elevation of a listener'"'"'s ear in the listening space.

10. The method of claim 8, further comprising decomposing the audio signal into the dry component and the reverberant component using a calculated estimate of an impulse response of a space in which the audio signal was captured.

11. The method of claim 8, where adjusting a level and a delay of an early reflection of only the reverberant component of the audio signal further comprises altering a listener perceived distance of the loudspeaker from the listener.

12. The method of claim 8, where outputting an adjusted audio output signal to drive a loudspeaker positioned above a listening position in the listening space comprises simulating an early reflection of a sound wave due to the ceiling of the listening space using the adjusted audio output signal.

13. The method of claim 8, further comprising receiving a microphone input signal and further adjusting at least one of the level or the delay of the early reflection of only the reverberant component of the audio signal based on the microphone input signal to further modify the listener perceived height of the ceiling of the listening space to substantially match a target listening space that is different than the listening space.

14. The method of claim 8, where the loudspeaker is position proximate an interior roof of a vehicle, and adjusting the level and the delay of an early reflection of only the reverberant component of the audio input signal comprises perceptually adjusting a height of the interior roof of the vehicle by driving the loudspeaker.

15. A computer readable storage medium that stores instructions executable by a processor to modify an acoustic space with audio source content, the computer readable storage medium comprising:

instructions executable by the processor to process an audio signal having a dry component and a reverberant component;

instructions executable by the processor to calculate an estimate of the direct component and an estimate of the reverberant component from the audio signal;

instructions executable by the processor to separately adjust early reflections of the estimated reverberant component to adjust a listener perceived height of a listening space, the early reflections separately adjusted based on a target listening space;

instructions executable by the processor to generate output frequency spectra based on the adjusted reverberant component and the dry component; and

instructions executable by the processor to generate an audio output channel from the frequency spectra, the audio output channel configured to drive a loudspeaker positioned above the listening space.

16. The computer readable storage medium of claim 15, further comprising instructions executable by the processor to separately adjust the early reflections by separate adjustment of delays applied to the early reflections.

17. The computer readable storage medium of claim 15, further comprising instructions executable by the processor to separately adjust the early reflections by separate adjustment of levels of the early reflections.

18. The computer readable storage medium of claim 15, further comprising instructions executable by the processor to separately adjust the early reflections by separate filtering of the early reflections to alter a frequency response of a combination of the direct signal component and the filtered reverberant signal component.

19. The computer readable storage medium of claim 15, where the audio channel is a first audio channel and the loudspeaker is a first loudspeaker, the computer readable storage medium further comprising:

instructions executable by the processor to adjust early reflections of the estimated reverberant component to adjust a listener perceived distance to a floor of the listening space; and

instructions executable by the processor to generate a second audio output channel from the frequency spectra, the second audio output channel configured to drive a second loudspeaker positioned in the listening space at an elevation below a listener'"'"'s ears.

20. The computer readable storage medium of claim 19, further comprising instructions executable by the processor to adjust the early reflections of the estimated reverberant component separately based on the target listening space.

21. The computer readable storage medium of claim 20, further comprising instructions executable by the processor to separately adjust the early reflections of the estimated reverberant component by separate adjustment of at least one of levels or delays of the early reflections of the estimated reverberant component.

22. The computer readable storage medium of claim 19, further comprising instructions executable by the processor to add a diffuse exponentially decaying system to the first audio signal and the second audio signal to reduce user perceived boundaries of the listening space.