We can compare the deep sleep state to a powered on tape recorder in recording mode. Since senses are fully at rest, though the recording mode is on, nothing is being recorded in absence of any signal. However since the tape is running, it will record ‘hiss’. In deep sleep our chitta (tape recorder) is not receiving any signal but is powered on by the presence of conciousness. So in Jagrut avastha, when the tape is played, the ignorance of deep sleep (blank tape) becomes evident. The tape recorder is powered by conciousness in all the 3 states.