System and method for providing a quiet zone
A system and method for quieting unwanted sound. As a non-limiting example, various aspects of this disclosure provide a system and method, for example implemented in a premises-based or home audio system, for quieting unwanted sound at a particular location.
1. An audio system comprising:
at least one module operable to, at least:
filter an audio signal to pass a frequency band of sound to be counteracted, wherein the frequency band is characterized by at least a lower bound;
identify an unwanted sound at a location, by, at least in part, operating to receive the unwanted sound using at least one sound sensor positioned at a distance away from the location at least one fourth of a wavelength of the lower bound of the frequency band of sound to be counteracted;
identify a loudspeaker to utilize to quiet the unwanted sound;
determine a counteracting sound that, when output by the loudspeaker, will quiet the unwanted sound at the location; and
output the counteracting sound at the loudspeaker.
2. The audio system of claim 1 , wherein the at least one module is operable to determine a direction of the unwanted sound, and to determine the counteracting sound based at least in part on the determined direction.
3. The audio system of claim 1 , wherein:
the at least one sound sensor comprises a first sound sensor positioned away from the location and a second sound sensor positioned away from the location;
the first sound sensor and the second sound sensor are both positioned at a distance away from the location at least one fourth of a wavelength of the lower bound of the frequency band of sound to be counteracted; and
the at least one module is operable to determine the direction of the unwanted sound by, at least in part, operating to determine the direction based at least in part on the unwanted sound received at each of the first and second sound sensors.
4. The audio system of claim 1 , wherein the at least one sound sensor comprises a microphone.
5. The audio system of claim 1 , wherein the at least one sound sensor comprises a plurality of microphones positioned at fixed geographical locations.
6. The audio system of claim 1 , wherein the at least one module is operable to identify the counteracting sound by, at least in part, operating to set a magnitude of the counteracting sound to a level below that determined for ideal cancellation.
7. An audio system comprising:
at least one module operable to, at least:
identify an unwanted sound to counteract;
analyze the identified unwanted sound by, at least in part, analyzing a first amount of frequency content that the identified unwanted sound has in a first frequency band and analyzing a second amount of frequency content that the identified unwanted sound has in a second frequency band;
select, based at least in part on the analysis of the identified unwanted sound, between a plurality of different types of countermeasure strategies for counteracting the unwanted sound; and
implement the selected strategy,
wherein the plurality of different types of countermeasure strategies comprises:
a first countermeasure strategy comprising performing sound cancellation; and
a second countermeasure strategy comprising performing sound masking.
8. The audio system of claim 7 , wherein the second countermeasure strategy comprises performing the sound masking with a randomized noise signal.
9. The audio system of claim 7 , wherein the plurality of different types of countermeasure strategies comprises a third countermeasure strategy comprising performing sound cancellation and sound masking on a same sound to be counteracted.
10. The audio system of claim 7 , wherein the at least one module is operable to:
filter an audio signal to pass a frequency band of sound to be counteracted, wherein the frequency band is characterized by at least a lower bound; and
identify the unwanted sound to counteract at a location utilizing a microphone that is positioned at a distance away from the location at least one fourth of a wavelength of the lower bound of the frequency band of sound to be counteracted.
11. The audio system of claim 7 , wherein the at least one module is operable to identify the unwanted sound to counteract utilizing a plurality of microphones positioned at fixed geographical locations.
12. The audio system of claim 9 , wherein the sound cancellation and the sound masking are performed in different and non-overlapping respective frequency bands.
13. The audio system of claim 7 , wherein the first countermeasure strategy comprises setting a magnitude of a cancellation signal 6-10 dB lower than the level determined for ideal cancellation.