An audio channel of a time-based media presentation provides a basis for synchronizing to the presentation across a variety of platforms independent of when and where the presentation is being viewed. By pre-processing the media into a series of non-unique hashes, and similarly processing an audio stream of the media captured at a client device, a comparison can be made that yields an accurate time offset within the presentation. The comparison may usefully be performed over a data network using a server that hosts data from the pre-processed media, and a variety of applications may be deployed on the client device based on the resulting synchronization.