Methods and apparatus to identify and credit media using ratios of media characteristics

1. An apparatus to identify media, comprising:

a delta calculator to:

determine a first ratio based on a first time interval and a second time interval of a monitored media signal; and

determine a second ratio based on the second time interval and a third time interval of the monitored media signal; and

a signature generator to:

generate a monitored media ratio signature based on the first and second ratios; and

initiate transmission of the monitored media ratio signature to a recipient that is to compare the monitored media ratio signature with a reference ratio signature to identify the media;

at least one of the delta calculator or the signal generator implemented by at least one of a processor or hardware.

2. The apparatus as defined in claim 1 , wherein the second time interval is subsequent to the first time interval.

3. The apparatus as defined in claim 1 , wherein the delta calculator is to divide the first time interval by the second time interval to determine the first ratio.

4. The apparatus as defined in claim 1 , wherein the delta calculator is to divide the first time interval by a sum of the first time interval and the second time interval to determine the first ratio.

5. The apparatus as defined in claim 1 , wherein the delta calculator is to divide the first time interval by a sum of the first time interval, the second time interval, and the third time interval of the monitored media signal to determine a third ratio.

6. The apparatus as defined in claim 1 , wherein the monitored media signal includes a plurality of time intervals, respective ones of the time intervals being between respective adjacent characteristics of the monitored media signal, the plurality of time intervals including the first time interval, the second time interval and the third time interval.

7. An apparatus to identify media, comprising:

means for determining ratios that is to determine a first ratio based on a first time interval and a second time interval of a monitored media signal, and to determine a second ratio based on the second time interval and a third time interval of the monitored media signal;

means for generating a monitored media ratio signature based on the first and second ratios; and

means for initiating transmission of the monitored media ratio signature to a recipient that is to compare the monitored media ratio signature with a reference ratio signature to identify the media.

8. The apparatus as defined in claim 7 , wherein the second time interval is subsequent to the first time interval.

9. The apparatus as defined in claim 7 , wherein the means for determining ratios is to divide the first time interval by the second time interval to determine the first ratio.

10. The apparatus as defined in claim 7 , wherein the means for determining ratios is to divide the first time interval by a sum of the first time interval and the second time interval to determine the first ratio.

11. The apparatus as defined in claim 7 , wherein the means for determining ratios is to divide the first time interval by a sum of the first time interval, the second time interval, and the third time interval of the monitored media signal to determine a third ratio.

12. The apparatus as defined in claim 7 , wherein the monitored media signal includes a plurality of time intervals, respective ones of the time intervals being between respective adjacent characteristics of the monitored media signal, the plurality of time intervals including the first time interval, the second time interval and the third time interval.

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

determine a first ratio based on a first time interval and a second time interval of a monitored media signal;

determine a second ratio based on the second time interval and a third time interval of the monitored media signal;

generate a monitored media ratio signature based on the first and second ratios; and

initiate comparison of the monitored media ratio signature with a reference ratio signature to identify the media.

14. The storage medium as defined in claim 13 , wherein the second time interval is subsequent to the first time interval.

15. The storage medium as defined in claim 13 , wherein the instructions, when executed, cause the machine to divide the first time interval by the second time interval.

16. The storage medium as defined in claim 13 , wherein the instructions, when executed, cause the machine to divide the first time interval by a sum of the first time interval and the second time interval of the monitored media signal.

17. The storage medium as defined in claim 13 , wherein the instructions, when executed, cause the machine to divide the first time interval by a sum of the first time interval, the second time interval, and the third time interval of the monitored media signal.

18. The storage medium as defined in claim 13 , wherein the monitored media signal includes a plurality of time intervals, respective ones of the time intervals being between respective adjacent characteristics of the monitored media signal, the plurality of time intervals including the first time interval, the second time interval and the third time interval.