Methods and apparatus to determine a location of an audio source

1. An apparatus to identify a physical location of an audio source, the apparatus comprising:

sensor circuitry to obtain audio signals from a plurality of microphones;

machine-readable instructions; and

at least one processor circuit to be programmed based on the machine-readable instructions to:

identify ordered microphone sets from the plurality of microphones, ones of the ordered microphone sets to include different permutations of the microphones, one of the microphones in a first ordered microphone set of the ordered microphone sets to be designated an origin microphone of the first ordered microphone set, and other ones of the microphones in the first ordered microphone set to be paired with the origin microphone to form microphone pairs of the first ordered microphone set;

calculate estimated source locations for the audio source based on the audio signals obtained by the sensor circuitry, a first one of the estimated source locations based on the audio signals from a first microphone pair of the microphone pairs of the first ordered microphone set;

calculate respective estimation errors for corresponding ones of the estimated source locations, a first one of the estimation errors for the first one of the estimated source locations based on a first individual error corresponding to the first microphone pair and at least a second individual error corresponding to a different microphone pair having a microphone not included in the first ordered microphone set;

calculate respective likelihood values for corresponding ones of the estimated source locations;

determine the physical location of the audio source based on the estimated source locations and the respective likelihood values; and

output the physical location of the audio source.

2. The apparatus of claim 1 , wherein one or more of the at least one processor circuit is to:

compare the respective likelihood values corresponding to the estimated source locations; and

select the first one of the estimated source locations to be used to represent the physical location of the audio source based on the comparison of the respective likelihood values.

3. The apparatus of claim 2 , wherein the first one of the estimated source locations has a highest likelihood value among the respective likelihood values corresponding to the estimated source locations.

4. The apparatus of claim 1 , wherein one or more of the at least one processor circuit is to calculate the first individual error based on a difference between a first distance and a second distance, the first distance determined based on time difference of arrival (TDOA) data and the second distance determined based on microphone positional data.

5. The apparatus of claim 4 , wherein a number of the microphones is greater than 5.

6. An apparatus to identify a physical location of an audio source, the apparatus comprising:

interface circuitry to access audio signals from a plurality of microphones;

instructions; and

at least one processor to be programmed based on the instructions to:

identify ordered microphone sets from the plurality of microphones;

determine estimated source locations for the audio source based on the audio signals accessed by the interface circuitry, a first one of the estimated locations based on the audio signals from a first microphone pair included in a first ordered microphone set of the ordered microphone sets;

calculate respective estimation errors for corresponding ones of the estimated source locations, a first one of the estimation errors for the first one of the estimated locations based on a first individual error corresponding to the first microphone pair and at least a second individual error corresponding to a different microphone pair having a microphone not included in the first ordered microphone set, the first individual error based on a difference between a first distance and a second distance, the first distance based on time difference of arrival (TDOA) data, and the second distance based on a difference between 1) a distance between the first one of the estimated source locations and a first position of a first microphone associated with the first individual error, and 2) a distance between the first one of the estimated source locations and a second position of a second microphone associated with the first individual error;

calculate respective likelihood values for corresponding ones of the estimated source locations;

determine the physical location of the audio source based on the estimated source locations and the respective likelihood values; and

output the physical location of the audio source.

7. The apparatus of claim 6 , wherein one or more of the at least one processor circuit is to:

compare the respective likelihood values corresponding to the estimated source locations; and

select the first one of the estimated source locations to represent the physical location of the audio source based on the comparison of the respective likelihood values.

8. The apparatus of claim 6 , wherein the first one of the estimated source locations has a highest likelihood value among the respective likelihood values corresponding to the estimated source locations.

9. The apparatus of claim 6 , wherein a number of the microphones is greater than 5.

10. The apparatus of claim 6 , wherein different ones of the ordered microphone sets include different permutations of microphones, one of the microphones in the first ordered microphone set of the ordered microphone sets to be designated an origin microphone, and other ones of the microphones in the first ordered set to be paired with the origin microphone to create microphone pairs of the first ordered microphone set.

11. A method to identify a physical location of an audio source, the method comprising:

identifying, by executing an instruction with at least one processor circuit, ordered microphone sets from a plurality of microphones;

calculating, with one or more of the at least one processor circuit, estimated source locations for the audio source based on audio signals obtained via sensor circuitry from the plurality of microphones, a first one of the estimated source locations based on the audio signals from a first microphone pair included in a first ordered microphone set of the ordered microphone sets;

calculating, with one or more of the at least one processor circuit, respective estimation errors for corresponding ones of the estimated source locations, a first one of the estimation errors for the first one of the estimated source locations based on a first individual error corresponding to the first microphone pair and at least a second individual error corresponding to a different microphone pair having a microphone not included in the first ordered microphone set, the first individual error based on a difference between a first distance and a second distance, the first distance based on time difference of arrival (TDOA) data, and the second distance based on a difference between 1) a distance between the first one of the estimated source locations and a first position of a first microphone associated with the first individual error, and 2) a distance between the first one of the estimated source locations and a second position of a second microphone associated with the first individual error; and

calculating respective likelihood values for corresponding ones of the estimated source locations;

determining the physical location of the audio source based on the estimated source locations and the respective likelihood values; and

outputting the physical location of the audio source.

12. The method of claim 11 , including:

comparing the respective likelihood values corresponding to the estimated source locations; and

selecting the first one of the estimated source locations to represent the physical location of the audio source based on the comparison of the respective likelihood values.

13. The method of claim 11 , wherein the first one of the estimated source locations has a highest likelihood value among the respective likelihood values corresponding to the estimated source locations.

14. The method of claim 11 , wherein a number of the microphones is greater than 5.

15. The method of claim 11 , wherein different ones of the ordered microphone sets include different permutations of microphones, one of the microphones in the first ordered microphone set of the ordered microphone sets being designated an origin microphone, and other ones of the microphones in the first ordered set being paired with the origin microphone to create microphone pairs of the first ordered microphone set.

16. At least one non transitory computer readable medium comprising computer readable instructions cause at least one processor circuit to at least:

identify ordered microphone sets from a plurality of microphones, ones of the ordered microphone sets to include different permutations of the microphones, one of the microphones in a first ordered microphone set of the ordered microphone sets to be designated an origin microphone of the first ordered microphone set, and other ones of the microphones in the first ordered microphone set to be paired with the origin microphone to form microphone pairs of the first ordered microphone set;

calculate estimated source locations for an audio source based on audio signals obtained by sensor circuitry coupled to the plurality of microphones, a first one of the estimated source locations based on the audio signals from a first microphone pair of the microphone pairs of the first ordered microphone set;

calculate respective estimation errors for corresponding ones of the estimated source locations, a first one of the estimation errors for the first one of the estimated source locations based on a first individual error corresponding to the first microphone pair and at least a second individual error corresponding to a different microphone pair having a microphone not included in the first ordered microphone set;

calculate respective likelihood values for corresponding ones of the estimated source locations;

determine physical location of the audio source based on the estimated source locations and the respective likelihood values; and

output the physical location of the audio source.

17. The at least one non-transitory computer readable medium of claim 16 , wherein the computer readable instructions are to cause one or more of the at least one processor circuit to:

compare the respective likelihood values corresponding to the estimated source locations; and

select the first one of the estimated source locations to represent the physical location of the audio source based on the comparison of the respective likelihood values.

18. The at least one non-transitory computer readable medium of claim 17 , the first one of the estimated source locations has a highest likelihood value among the respective likelihood values corresponding to the estimated source locations.

19. The at least one non-transitory computer readable medium of claim 16 , wherein the computer readable instructions are to cause one or more of the at least one processor circuit to calculate the first individual error based on a difference between a first distance and a second distance, the first distance determined based on time difference of arrival (TDOA) data and the second distance determined based on microphone positional data.

20. The at least one non-transitory computer readable medium of claim 19 , wherein a number of the microphones is greater than 5.