1. An apparatus to identify media, the apparatus comprising: a signature receiver, implemented by a circuit, to receive a monitored media signature from a meter that is to monitor an output device, the monitored media signature based on a media signal associated with a presentation of the media by the output device; a delta extractor, implemented by a circuit, to: determine a first ratio based on a first time interval and a second time interval of the monitored media signature, the monitored media signature including a plurality of time intervals, respective ones of the time intervals being between respective adjacent characteristics identified in the media; determine a second ratio based on a third time interval and a fourth time interval of the monitored media signature; and generate a monitored media ratio signature based on the first and second ratios; a signature comparator, implemented by a circuit, to compare the monitored media ratio signature with a reference ratio signature in a reference ratio signature database to identify the media independent of a rate at which the output device presented the media; and a media creditor, implemented by a circuit, to credit the identified media as being presented by the output device.