Methods and apparatus to determine a state of a media presentation device

• US 10,735,809 B2
• Filed: 03/19/2018
• Issued: 08/04/2020
• Est. Priority Date: 04/03/2015
• Status: Active Grant

• Current Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Original Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Inventors: Srinivasan, Venugopal, Lee, Morris, Davis, Jeremey M.
• Primary Examiner(s): Tran, Hai V
• Application Number:
  US15/925,360
• Publication Number:
  US 20180213281A1
• Time in Patent Office: 869 Days
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: G10L 25/51 for comparison or discrimination
• CPC Class Codes: H04H 2201/50 characterised by the use of watermarks
• CPC Class Codes: H04H 2201/90 characterised by the use of signatures
• CPC Class Codes: H04H 60/37 for identifying segments of broadcast information, e.g. scenes or extracting programme ID
• CPC Class Codes: H04H 60/58 of audio determination or detection of speech characteristics in general G10L25/00; speech recognition in general G10L15/00
• CPC Class Codes: H04H 60/65 for using the result on users' side
• 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 21/44213 Monitoring of end-user related data arrangements for monitoring the users' behaviour or opinions in broadcast systems H04H60/33
• CPC Class Codes: H04N 21/8106 involving special audio data, e.g. different tracks for different languages

Abstract

Methods and apparatus to determine a state of a media presentation device are disclosed. Example disclosed methods include generating a first set of weighted coefficients based on first audio received by first and second microphones at a first time. Example disclosed methods include generating a second set of weighted coefficients based on second audio received by the first and second microphones at a second time after the first time. Example disclosed methods include comparing the first set of coefficients and the second set of coefficients to generate a similarity value. Example disclosed methods include, when the similarity value satisfies a threshold, determining that the media presentation device is in a first state. Example disclosed methods include, when the similarity value does not satisfy the threshold, determining that the media presentation device is in a second state.

Claims

1. An apparatus to determine a source of a first audio signal sensed by a first microphone, the apparatus comprising:

memory to store instructions; and

at least one processor to execute the instructions to at least;

compare the first audio signal to a second audio signal from a second microphone to generate a first set of weighted coefficients, the first microphone and the second microphone positioned with respect to a first source;

compare the first set of weighted coefficients to a second set of weighted coefficients of a reference audio signal to generate a similarity value, the reference audio signal based on audio sensed by the first microphone and by the second microphone and originated from the first source; and

identify the source of the first audio signal as the first source in response to the similarity value satisfying a threshold.

2. The apparatus of claim 1, wherein the at least one processor is further to control a metering device associated with the first source to capture media exposure data from the first source in response to the at least one processor identifying the source of the first audio signal as the first source.

3. The apparatus of claim 2, wherein the media exposure data includes a watermark extracted from the first audio signal.

4. The apparatus of claim 1, wherein the at least one processor is to compare the first set of weighted coefficients and the second set of weighted coefficients to generate the similarity value by calculating a dot product between the first set of weighted coefficients and the second set of weighted coefficients.

5. The apparatus of claim 1, wherein the at least one processor is further to:

generate an error signal based on a comparison of the second set of weighted coefficients to a third set of weighted coefficients of an updated reference signal originating from the first source; and

replace the second set of weighted coefficients with the third set of weighted coefficients when the error signal exceeds an error threshold.

6. The apparatus of claim 5, wherein the at least one processor is to generate the error signal according to X_e(n)=X_d(n)−

Y₀(n), the X_d(n) representing an audio sample and the Y₀(n) representing a summed filter output of multiple audio samples, the n being an iteration index, and the at least one processor to work with a weight adjuster to adjust the first set of weighted coefficients based on the error signal according to W_m(n+1)=W_m(n)+μ

X_eX_m(n), the W_m(n+1) and the W_m being weight coefficients, X_m(n) being a weighted audio sample, and the μ

being a learning factor.

7. The apparatus of claim 1, wherein the at least one processor is to generate the first and second sets of weighted coefficients with an adaptive echo cancellation algorithm implemented with a finite impulse response filter.

8. The apparatus of claim 1, wherein the at least one processor is to filter one of the first audio signal or the second audio signal for comparison to another of the first audio signal or the second audio signal.

9. A computer readable storage medium comprising instructions that, when executed, cause a machine to at least:

compare a first audio signal from a first microphone to second audio from a second microphone to generate a first set of weighted coefficients, the first microphone and the second microphone positioned with respect to a first source;

compare the first set of weighted coefficients to a second set of weighted coefficients of a reference audio signal to generate a similarity value, the reference audio signal based on audio originated from the first source; and

identify the source of the first audio signal as the first source when the similarity value satisfies a threshold.

10. The computer readable storage medium of claim 9, wherein the instructions, when executed, further cause the machine to control a metering device associated with the first source to capture media exposure data from the first source in response to identifying the source of the first audio signal as the first source.

11. The computer readable storage medium of claim 9, wherein the instructions, when executed, cause the machine to compare the first set of weighted coefficients and the second set of weighted coefficients to generate the similarity value by calculating a dot product between the first set of weighted coefficients and the second set of weighted coefficients to generate the similarity value.

12. The computer readable storage medium of claim 9, wherein the instructions, when executed, cause the machine to:

generate an error signal based on a comparison of the second set of weighted coefficients to a third set of weighted coefficients of an updated reference signal originating from the first source; and

replace, when the error signal exceeds an error threshold, the second set of weighted coefficients with the third set of weighted coefficients for comparison to the first set of weighted coefficients for the first audio signal.

13. The computer readable storage medium of claim 12, wherein the instructions, when executed, cause the machine to generate the error signal by generating the error signal, X_e(n), according to X_e(n)=X_d(n)−

Y₀(n), the X_d(n) representing an audio sample and the Y₀(n) representing a summed filter output of multiple audio samples, the n being an iteration index, and the first set of weighted coefficients to be adjusted based on the error signal according to to W_m(n+1)=W_m(n)+μ

X_eX_m(n), the W_m(n+1) and the W_m being weight coefficients, X_m(n) being a weighted audio sample, and the μ

being a learning factor.

14. The computer readable storage medium of claim 9, wherein the instructions, when executed, cause the machine to generate the first and second sets of weighted coefficients based on an adaptive echo cancellation algorithm applied by a finite impulse response filter.

15. The computer readable storage medium of claim 9, wherein the instructions, when executed, cause the machine to filter one of the first audio signal or the second audio for comparison to another of the first audio signal or the second audio.

16. An apparatus to determine a source of a first audio signal sensed by a first microphone, the apparatus comprising:

means for comparing the first audio signal to a second audio signal from a second microphone to generate a first set of weighted coefficients, the first microphone and the second microphone positioned with respect to a first source; and

means for comparing the first set of weighted coefficients to a second set of weighted coefficients of a reference audio signal to generate a similarity value, the reference audio signal based on audio sensed by the first microphone and by the second microphone and originated from the first source; and

means for identifying the source of the first audio signal as the first source in response to the similarity value satisfying a threshold.

17. The apparatus of claim 16, further including means for controlling a metering device associated with the first source to capture media exposure data from the first source in response to identifying the source of the first audio signal as the first source.

18. The apparatus of claim 16, further including means for generating an error signal based on a comparison of the second set of weighted coefficients to a third set of weighted coefficients of an updated reference signal originating from the first source and replacing the second set of weighted coefficients with the third set of weighted coefficients when the error signal exceeds an error threshold.

19. The apparatus of claim 18, further including means to adjust weights applied to at least one of the first set of weighted coefficients or the second set of weighted coefficients based on the error signal.

20. The apparatus of claim 16, further including means for filtering one of the first audio signal or the second audio signal for comparison to another of the first audio signal or the second audio signal.