>Muse uses 7 finely calibrated EEG sensors to detect and measure the activity of your brain. This sensory input is translated into real-time feedback on your tablet or smart phone via Bluetooth. The result is a rich, real-time audio and visual experience. Calibrated for whom?
http://www.choosemuse.com/pages/faq#using
says that there is a 1 minute calibration period at the beginning of each use.