METHODS AND APPARATUS TO DETECT SPILLOVER IN AN AUDIENCE MONITORING SYSTEM

• US 20140282663A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Original Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Inventors: Lee, Morris
• Granted Patent: US 9,197,930 B2
• Time in Patent Office: Days
• US Class Current: 725/18
• CPC Class Codes: G01S 3/808 using transducers spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 3/8083 determining direction of source
• CPC Class Codes: H04N 21/25891 being end-user preferences retrieval of video data in a video database based on user preferences G06F16/739; arrangements for recognizing users' preferences H04H60/46; user profiles in network data switching protocols H04L67/306; processing of user preferences or user profiles in wireless networks H04W8/18
• CPC Class Codes: H04N 21/42203 sound input device, e.g. microphone
• CPC Class Codes: H04N 21/4394 involving operations for analysing the audio stream, e.g. detecting features or characteristics in audio streams arrangements characterised by components specially adapted for monitoring, identification or recognition of audio in broadcast systems H04H60/58
• CPC Class Codes: H04N 21/44204 Monitoring of content usage, e.g. the number of times a movie has been viewed, copied or the amount which has been watched monitoring of user activities for profile generation for accessing a video database G06F16/739; protecting generic digital content where the protection is independent of the precise nature of the content G06F21/10; arrangements for monitoring the use made of the broadcast services in broadcast systems H04H60/31
• CPC Class Codes: H04N 21/44213 Monitoring of end-user related data arrangements for monitoring the users' behaviour or opinions in broadcast systems H04H60/33
• CPC Class Codes: H04N 21/8352 involving content or source identification data, e.g. Unique Material Identifier [UMID]
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

Methods and apparatus to detect spillover in an audience monitoring system are disclosed. An example method includes sampling a first audio signal from a first source received by a first microphone; sampling a second audio signal received by a second microphone from the first source, wherein the second microphone is separated from the first microphone by a first distance; calculating an origin direction of the first source based on a time difference between receipt of the first and second audio signals; when the origin direction is within a threshold angle, retaining the media associated with the first source; and when the origin direction exceeds the threshold angle, ignoring the media associated with the first source

Claims

1. A method to distinguish local media from spillover media content comprising:

sampling a first audio signal from a first source received by a first microphone;

sampling a second audio signal received by a second microphone from the first source, wherein the second microphone is separated from the first microphone by a first distance;

calculating an origin direction of the first source based on a time difference between receipt of the first and second audio signals;

when the origin direction is within a threshold angle, retaining the media associated with the first source; and

when the origin direction exceeds the threshold angle, ignoring the media associated with the first source.

4. A method as defined in claim 1, further comprising:

calculating an absolute value of the first audio signal and the second audio signal; and

applying a first and second decimation threshold to the first and second audio signals, respectively.

5. A method as defined in claim 4, further comprising:

removing samples from the first audio signal with intensities below the first decimation threshold; and

removing samples from the second audio signal with intensities below the second decimation threshold.

6. A method as defined in claim 5, wherein the first and second decimation thresholds are determined such that removing samples from the first and second audio signals removes a majority of the samples from the first and second audio signals.

7. A method as defined in claim 1, further comprising:

calculating a moving average of the first and second audio signals;

selecting a first set of samples from the first audio signal;

selecting a second set of samples from the second audio signal; and

determining a first correlation value between the first set of samples and the second set of samples.

8. A method as defined in claim 7, wherein each point of the moving average of the first and second audio signals comprises an average of two samples from the first and second audio signals, respectively.

9. A method as defined in claim 7, wherein the first set of samples comprises samples from the first audio signal that are equally spaced between a first point in time and a second point in time.

10. A method as defined in claim 9, wherein the second set of samples comprises samples from the second audio signal that are equally spaced between the first point in time and the second point in time.

11. A method as defined in claim 10, further comprising:

selecting a third set of samples from the second audio signal, wherein the third set of samples is offset from the second set of samples by a first number of samples; and

determining a second correlation value between the first set of samples and the third set of samples.

12. A method as defined in claim 11, wherein the time difference is determined by determining the greater of the first correlation value and the second correlation value.

13. A method as defined in claim 9, further comprising selecting a fourth set of samples from the first audio signal, wherein the fourth set of samples is offset from the first set of samples by a first time.

2-3. -3. (canceled)

14. A tangible machine readable storage medium comprising instructions that, when executed, cause the machine to at least:

sample a first audio signal from a first source received by a first microphone;

sample a second audio signal received by a second microphone from the first source, wherein the second microphone is separated from the first microphone by a first distance;

calculate an origin direction of the first source based on a time difference between receipt of the first and second audio signals;

when the origin direction is within a threshold angle, retain media associated with the first source; and

when the origin direction exceeds the threshold angle, ignore the media associated with the first source.

16. A machine readable storage medium as defined in claim 14, wherein the threshold angle is based on the physical location of the first source associated with the media.

20. A machine readable storage medium as defined in claim 14, wherein the instructions cause the machine to:

calculate a moving average of the first and second audio signals;

select a first set of samples from the first audio signal;

select a second set of samples from the second audio signal; and

determine a first correlation value between the first set of samples and the second set of samples.

15. (canceled)

17-19. -19. (canceled)

21-26. -26. (canceled)

27. An apparatus to distinguish local media from spillover media comprising:

an audio sampler to sample a first audio signal from a first source received by a first microphone and sample a second audio signal received by a second microphone from the first source, wherein the second microphone is separated from the first microphone by a first distance;

a direction detector to calculate an origin direction of the first source based on a time difference between receipt of the first and second audio signals; and

a filter to retain the media associated with the first source when the origin direction is within a threshold angle and ignore the media associated with the first source when the origin direction exceeds the threshold angle.

28. An apparatus as defined in claim 27, wherein the first source is a media device.

29. An apparatus as defined in claim 27, wherein the threshold angle is based on the physical location of the first source associated with the media.

30. An apparatus as defined in claim 27, further comprising:

an absolute value calculator to calculate an absolute value of the first audio signal and the second audio signal; and

a threshold processor to apply a first and second decimation threshold to the first and second audio signals, respectively.

33. An apparatus as defined in claim 27, further comprising:

a moving average calculator to calculate a moving average of the first and second audio signals;

an audio sample selector to select a first set of samples from the first audio signal;

an audio signal delayer to select a second set of samples from the second audio signal; and

a correlation engine to determine a first correlation value between the first set of samples and the second set of samples.

35. An apparatus as defined in claim 33, wherein the audio sample selector selects samples from the first audio signal that are equally spaced between a first point in time and a second point in time.

36. An apparatus as defined in claim 35, wherein the audio signal delayer selects samples from the second audio signal that are equally spaced between the first point in time and the second point in time.

38. An apparatus as defined in claim 36, further comprising an offset selector to determine the time difference by determining the greater of the first correlation value and the second correlation value.

31-32. -32. (canceled)

34. (canceled)

37. (canceled)

39. (canceled)