Methods, systems, and apparatus to calculate distance from audio sources

1. A method to reduce battery consumption of a portable audio collecting device, comprising:

transmitting a first radio frequency (RF) signal from the portable audio collecting device to prompt a reference audio collecting device to begin collecting audio samples from an audio source at a first time, the audio source being closer to the reference audio collecting device than to the portable audio collecting device;

initiating a dwell period in response to the first RF signal to reduce battery consumption of the portable audio collecting device by preventing the portable audio collecting device from collecting audio samples from the audio source at the first time, the dwell period being based on a distance between the portable audio collecting device and the reference audio collecting device; and

when the dwell period expires, prompting the portable audio collecting device to collect audio samples from the audio source at a second time.

2. A method as defined in claim 1 , further including collecting audio samples from the audio source with the portable audio collecting device for a portable collection duration between the second time and a third time.

3. A method as defined in claim 2 , wherein the portable collection duration of the portable audio collecting device is less than a reference collection duration between the first time and the third time.

4. A method as defined in claim 3 , further including setting the dwell period to cause overlap parity between (a) audio samples collected from the audio source by the portable audio collecting device during the portable collection duration and (b) audio samples collected from the audio source by the reference audio collecting device during the reference collection duration.

5. A method as defined in claim 1 , further including associating respective ones of the audio samples collected from the audio source with an indication of a respective time of acquisition.

6. A method as defined in claim 5 , wherein the respective time of acquisition corresponds to an integer number of collected data samples.

7. A method as defined in claim 6 , wherein respective ones of the collected data samples are separated by a known sample duration.

8. A method as defined in claim 1 , further including selecting the dwell period based on a maximum distance between the portable audio collecting device and the reference audio collecting device.

9. A method as defined in claim 8 , wherein the maximum distance is based on a room size.

10. An apparatus to reduce battery consumption of a portable audio collecting device, comprising:

a radio frequency (RF) transmitter to transmit a first RF signal from the portable audio collecting device to prompt a reference audio collecting device to begin collecting audio samples from an audio source at a first time, the audio source being closer to the reference audio collecting device than to the portable audio collecting device; and

a timer to initiate a dwell period in response to the first RF signal to reduce battery consumption of the portable audio collecting device by preventing an audio sensor of the portable audio collecting device from collecting audio samples from the audio source at the first time, the dwell period being based on a distance between the portable audio collecting device and the reference audio collecting device, the timer to prompt the portable audio collecting device to collect audio samples from the audio source at a second time when the dwell period expires.

11. An apparatus as defined in claim 10 , wherein the audio sensor is to collect audio samples from the audio source for a portable collection duration between the second time and a third time.

12. An apparatus as defined in claim 11 , wherein the portable collection duration of the portable audio collecting device is less than a reference collection duration between the first time and the third time.

13. An apparatus as defined in claim 12 , further including a correlation engine to set the dwell period to cause overlap parity between (a) audio samples collected from the audio source by the portable audio collecting device during the portable collection duration and (b) audio samples collected from the audio source by the reference audio collecting device during the reference collection duration.

14. An apparatus as defined in claim 10 , wherein the portable audio collecting device is to associate respective ones of the audio samples collected from the audio source with an indication of a respective time of acquisition.

15. An apparatus as defined in claim 14 , wherein the respective time of acquisition corresponds to an integer number of collected data samples.

16. An apparatus as defined in claim 15 , wherein respective ones of the collected data samples are separated by a known sample duration.

17. An apparatus as defined in claim 10 , further including a correlation engine to select the dwell period based on a maximum distance between the portable audio collecting device and the reference audio collecting device.

18. An apparatus as defined in claim 17 , wherein the correlation engine is to determine the maximum distance based on a room size.

19. A computer-readable storage device or storage disk comprising machine-readable instructions that, when executed, cause a machine to at least:

transmit a first radio frequency (RF) signal from a portable audio collecting device to prompt a reference audio collecting device to begin collecting audio samples from an audio source at a first time, the audio source being closer to the reference audio collecting device than to the portable audio collecting device;

initiate a dwell period in response to the first RF signal to reduce battery consumption of the portable audio collecting device by preventing the portable audio collecting device from collecting audio samples from the audio source at the first time, the dwell period being based on a distance between the portable audio collecting device and the reference audio collecting device; and

when the dwell period expires, prompt the portable audio collecting device to collect audio samples from the audio source at a second time.

20. A computer-readable storage device or storage disk as defined in claim 19 , wherein the instructions, when executed, cause a machine to collect audio samples from the audio source with the portable audio collecting device for a portable collection duration between the second time and a third time.

21. A computer-readable storage device or storage disk as defined in claim 20 , wherein the instructions, when executed, cause a machine to set the dwell period to cause overlap parity between (a) audio samples collected from the audio source by the portable audio collecting device during the portable collection duration and (b) audio samples collected from the audio source by the reference audio collecting device during a reference collection duration between the first time and the third time.

22. A computer-readable storage device or storage disk as defined in claim 19 , wherein the instructions, when executed, cause a machine to associate respective ones of the audio samples collected from the audio source with an indication of a respective time of acquisition.

23. A computer-readable storage device or storage disk as defined in claim 22 , wherein the instructions, when executed, cause a machine to associate the respective time of acquisition with an integer number of collected data samples.

24. A computer-readable storage device or storage disk as defined in claim 19 , wherein the instructions, when executed, cause a machine to select the dwell period based on a maximum distance between the portable audio collecting device and the reference audio collecting device.