Format
The original beep test was first only available on audio tape format. A problem with the tape was that it could stretch over time, or the tape player did not play at a consistent speed, therefore making the timing between beeps inaccurate. On most versions of the tape there was a one minute recorded interval for calibrating the tape and tape player. Digital audio formats are now used predominantly. Calibration checks are still required on the CD/MP3 due to some tone controls affecting the playback speed.
Inexpensive PC Beep Test Software is very popular with the advantage of no timing errors/accurate to 1/100th of a second, as used by the top team coaches. This generally runs on a Laptop, making the beep/bleep test easier to organise for teams/groups and also tracks player fitness over the season.
Read more about this topic: Multi-stage Fitness Test