Methods and apparatus to detect spillover
View Patent ↗Methods and apparatus to improve the accuracy of crediting media exposure through detecting reverberation indicative of spillover are disclosed. An example apparatus includes a reverberation analyzer to identify a quantity of short durations of loudness in an audio signal of media presented by a media presentation device and calculate a ratio of the quantity of the short durations of loudness to a quantity of durations of loudness in the audio signal of the media, the quantity of the durations of loudness including the quantity of short durations of loudness. The example apparatus also includes a processor and memory in circuit with the processor, the memory including instructions that, when executed by the processor, cause the processor to mark the media as un-usable to credit a media exposure when the ratio does not satisfy a loudness ratio threshold.
1. An apparatus comprising:
means for determining a ratio of a quantity of periods of loudness that satisfy a duration threshold and a total number of the periods of loudness, the periods of loudness corresponding to an audio signal of media presented by a media presentation device; and
means for marking the media as un-usable to credit a media exposure when the ratio does not satisfy a loudness ratio threshold, the marking of the media to improve an accuracy of the media exposure credit by excluding media having indications of spillover.
2. The apparatus of claim 1 , wherein the means for determining the ratio is to determine the periods of loudness in the audio signal of the media by detecting a first transition and a second transition in the audio signal of the media.
3. The apparatus of claim 2 , wherein the means for determining the ratio is to detect the second transition occurs when a loudness flag transitions from a loud-indicator value to a quiet-indicator value.
4. The apparatus of claim 3 , wherein the loudness flag is set to the quiet-indicator value when a sample of the audio signal satisfies a quiet threshold, the quiet threshold being based on a most recent peak value of the audio signal.
5. The apparatus of claim 2 , wherein the means for determining the ratio is to detect the first transition when a loudness flag transitions from a quiet-indicator value to a loud-indicator value.
6. The apparatus of claim 5 , wherein the loudness flag is set to the loud-indicator value when a sample of the audio signal satisfies a loud threshold, the loud threshold being based on a most recent dip value of the audio signal.
7. The apparatus of claim 2 , wherein the means for determining the ratio is to calculate a duration of one of the periods of loudness by determining a number of samples of the audio signal between the first transition and the second transition of the one of the periods of loudness.
8. A method comprising:
determining a quantity of short durations of loudness in an audio signal of media presented by a media presentation device;
determining a ratio of the quantity of the short durations of loudness to a quantity of durations of loudness in the audio signal of the media, the quantity of the durations of loudness including the quantity of short durations of loudness; and
storing data denoting the media as un-usable to credit a media exposure based on the audio signal being spillover when the ratio does not satisfy a loudness ratio threshold, the storing of the data to improve an accuracy of the media exposure credit by excluding media having indications of spillover.
9. The method of claim 8 , wherein the short durations of loudness are identified based on a duration threshold.
10. The method of claim 8 , further including:
determining the durations of loudness in the audio signal of the media by identifying a first transition when a loudness flag transitions from a quiet-indicator value to a loud-indicator value, and identifying a second transition in the audio signal of the media when the loudness flag transitions from the loud-indicator value to the quiet-indicator value; and
determining a duration of one of the durations of loudness as a number of samples of the audio signal between the first transition and the second transition.
11. The method of claim 10 , wherein the loudness flag is set to the quiet-indicator value when a sample of the audio signal satisfies a quiet threshold and a quiet length satisfies a quiet length threshold.
12. The method of claim 11 , further including:
incrementing the quiet length when the sample of the audio signal satisfies the quiet threshold; and
setting the quiet length to zero when the sample of the audio signal does not satisfy the quiet threshold.
13. The method of claim 10 , wherein the loudness flag is set to the loud-indicator value when a difference between a current sample of the audio signal and a previous sample of the audio signal satisfies a loud threshold, the loud threshold being based on a most recent dip value of the audio signal.
14. An apparatus comprising:
a reverberation analyzer to determine periods of loudness in an audio signal by:
determining whether a difference between a first amplitude at a first time and a second amplitude at a second time satisfies a loudness threshold;
in response to the difference satisfying the loudness threshold, setting a loudness flag to a loud state corresponding to the second time, the second time occurring after the first time;
determining whether a third amplitude at a third time after the second time satisfies a quiet threshold;
in response to the third amplitude satisfying the quiet threshold, setting the loudness flag to a quiet state corresponding to the third time; and
determining periods of loudness for the audio signal based on the states of the loudness flag at the second and third times; and
a spillover detector to indicate the audio signal as spillover based on the periods of loudness.
15. The apparatus of claim 14 , wherein the reverberation analyzer is to determine a short period of loudness based on a number of consecutive times in the audio signal during which the loudness flag is set to the loud state not satisfying a long threshold associated with long periods of loudness.
16. The apparatus of claim 15 , wherein the reverberation analyzer is to determine a quantity of short periods of loudness and a quantity of periods of loudness.
17. The apparatus of claim 16 , wherein the reverberation analyzer is to calculate a ratio of the short periods of loudness to the quantity of periods of loudness.
18. The apparatus of claim 16 , wherein the reverberation analyzer is to:
determine whether a fourth amplitude at a fourth time satisfies a quiet threshold;
in response to the fourth amplitude at the fourth time satisfying the quiet threshold, determine whether a number of consecutive times surrounding the fourth time satisfy the quiet threshold; and
in response to the number of consecutive times surrounding the fourth time satisfying the quiet threshold, set the loudness flag at the fourth time in the audio signal to the quiet state.
19. The apparatus of claim 18 , wherein the reverberation analyzer is to, in response to the number of consecutive times surrounding the fourth time satisfying the quiet threshold, set the loudness flag to the quiet state for ones of the consecutive times surrounding the fourth time satisfying the quiet threshold.
20. The apparatus of claim 14 , wherein the quiet threshold is a value relative to an amplitude at an initial time at which the loudness flag was set to the loud state.