Detector apparatus multiple sheets automated banking machine and method

Apparatus comprising: a transmitter (120) acoustic operative to transmit a sound wave through means (102) sheet, a receiver (122) acoustic operative to produce at least one receiver signal in response to acusticadespues wave that acoustic wave has passed through sheet media; a circuit (150, 152, 154) filter; and at least one processor (170) operative in response to at least one output of the filter circuit for representative determinardatos at least a phase change of the acoustic wave caused by passage through meansof sheet, wherein the at least a processor is operating in response to the determined data to determine media silos sheet through which it has passed the acoustic wave comprise at least one of a hojaindividual and multiple, characterized leaves because the filter circuit is operative to filter the at least a receiver with respect to two reference signals which differ in phase by substantially 90 degrees signal by.