Methods and apparatus to verify presentation of media content

1. An apparatus for use with a set-top box (STB) and a media presentation device, comprising:

means for interfacing an input to receive a first audio signal associated with a program selected by a user via the STB;

means for transducing to receive a free-field radiating second audio signal output by at least one of the media presentation device or an audio system associated with the media presentation device;

means for filtering having adaptive coefficients to delay and to attenuate the first audio signal to form an estimate of the second audio signal;

means for comparing to compare the second audio signal to the estimate of the second audio signal to form an output;

means for protecting privacy to facilitate burst mode operation of the means for comparing by periodically disabling the means for transducing and the means for comparing; and

means for interfacing an output to provide a value indicative of whether the program selected by the user via the STB is presented at the media presentation device based on the output.

2. The apparatus as defined in claim 1 , further including:

first means for connecting to communicatively couple the first audio signal from the STB to the apparatus via a first cable;

second means for connecting to communicatively couple the first audio signal from the apparatus to the media presentation device via a second cable; and

third means for connecting to provide the value via a third cable.

3. The apparatus as defined in claim 1 , further including means for interfacing an audio output to provide the received first audio signal to the media presentation device.

4. The apparatus as defined in claim 1 , further including first means for housing to contain the input interfacing means, the transducing means, the comparing means and the output interfacing means, wherein the first means for housing (first housing) is distinct from second means for housing to contain the STB and is also distinct from third means for housing to contain the media presentation device.

5. The apparatus as defined in claim 1 , further including first means for housing (a first housing) to contain the input interfacing means, the transducing means, the comparing means and the output interfacing means and the STB, and second means for housing to contain the media presentation device.

6. The apparatus as defined in claim 1 , wherein the value indicates a first logic state when the program selected via the STB is output via the media presentation device and indicates a second logic state when the program selected via the STB is not output via the media presentation device.

7. The apparatus as defined in claim 1 , wherein the comparing means includes means for cancelling echo.

8. The apparatus as defined in claim 1 , wherein the output of the comparing means represents a magnitude of a residual signal.

9. The apparatus as defined in claim 1 , wherein the comparing means includes means for subtracting to subtract the estimate of the second audio signal from the second audio signal to form a residual signal.

10. The apparatus as defined in claim 9 , wherein the comparing means further includes means for adapting to adjust at least one of the adaptive coefficients to reduce the magnitude of the residual signal.

11. The apparatus as defined in claim 9 , wherein the comparing means further includes means for thresholding to compare an absolute value of the residual signal to a threshold to form the output of the comparing means.

12. An apparatus for use with a set-top box (STB) and a media presentation device comprising:

means for interfacing an input to receive a first audio signal associated with a program selected by a user via the STB;

means for transducing to receive a free-field radiating second audio signal output by at least one of the media presentation device or an audio system associated with the media presentation device;

means for comparing to compare the second audio signal to the first audio signal to form an output;

means for interfacing an output to provide a value indicative of whether the program selected by the user via the STB is presented at the media presentation device based on the output; and

means for protecting privacy including means for timing to facilitate burst mode operation of the comparing means by periodically disabling the transducing means and the comparing means.

13. The apparatus as defined in claim 12 , wherein the apparatus is to be installed in-line between an audio output jack of the STB and an audio input jack of the media presentation device.

14. An apparatus to generate media presentation information, the apparatus comprising:

means for comparing to periodically output a value indicative of whether media selected via a set-top box is presented at a media presentation location, by the means for comparing comparing a first audio signal associated with media of a media presentation device to ambient audio received in the media presentation location via an audio system associated with the media presentation device;

means for protecting privacy to facilitate operation of the means for comparing by periodically preventing the means for comparing from receiving the ambient audio from a means for transducing for a first time period based on a granularity of the media presentation information that is to be reported, the granularity based on an amount of time, and enabling the means for comparing to receive the ambient audio from the means for transducing after the first time period expires; and

means for metering to record presentation of the media based on the output.

15. The apparatus as defined in claim 14 , wherein the privacy protecting means further includes means for timing to facilitate the operation of the comparing means by periodically disabling the transducing means.

16. An apparatus to generate media presentation information, the apparatus comprising:

means for comparing to periodically output a value indicative of whether media selected via a set-top box is presented at a media presentation location by comparing a first audio signal associated with the media to ambient audio received in the media presentation location via an audio system associated with a media presentation device;

means for protecting privacy to facilitate operation of the comparing means by periodically preventing the comparing means from receiving the ambient audio from means for transducing for a first time period based on a granularity of the media presentation information that is to be reported, the granularity based on an amount of time, and enabling the comparing means to receive the ambient audio from the transducing means after the first time period expires;

means for metering to record presentation of the media based on the output;

means for filtering to form an estimate of the ambient audio by delaying and attenuating the first audio signal, and

the comparing means to compare the estimate of the ambient audio to the ambient audio to form the output, wherein the filtering means to have adaptive weights to delay and to attenuate the first audio signal.

17. The apparatus as defined in claim 16 , wherein the filtering means is to set the adaptive weights to zero when the receiving of the ambient audio is enabled.

18. The apparatus as defined in claim 16 , wherein the comparing means is to form the output by subtracting the estimate of the ambient audio from the ambient audio to form a residual signal.

19. The apparatus as defined in claim 18 , wherein the comparing means is to compare the residual signal to a threshold.

20. The apparatus as defined in claim 16 , wherein the output represents whether the estimate of the ambient audio is present in the ambient audio.