How does SMPTE work?

SMPTE is audio timing content, also known as "timecode", that resides in the audio file that could be WAV, MP3, or any other audio format. The SMPTE audio file, when played, does not sound like music. Instead, SMPTE sounds like a squealing noise that is unrecognizable to the human ear. However, to the COBRA 18R2 or other systems receiving the SMPTE audio feed, it contains valuable timing information. The SMPTE is basically an audio file "stopwatch". For example, at 0 seconds, the SMPTE audio is sending 0 seconds and at 10 seconds, the SMPTE audio is sending 10 seconds. If you were to slide the play-bar on your audio player and stop at a defined time, the output signal would contain an audio representation of the time you are currently playing at. As the audio file plays, it's sending new timing information continuously. The system who is receiving this audio timing feed will interpret the data and execute its own internal systems at the same time as the audio timing values it's receiving. You can download a sample 90 minute SMPTE time code MP3 file. This file can be used for any shows up to 90 minutes long.