Methods and apparatus to dynamically generate audio signatures adaptive to circumstances associated with media being monitored are disclosed. An example apparatus includes a signal selector to select a first signature scheme from among a plurality of signature schemes to generate monitored signatures for media being monitored by a meter. The first signature scheme is selected based on a circumstance associated with the media. The apparatus includes a signal generator to generate a first monitored signature from the media based on the first signature scheme. The apparatus further includes a communications interface to transmit the first monitored signature to a data collection facility.