A first contact and a second contact are provided at each of a plurality of keys, and are successively closed in accordance with a key press operation. On the basis of respective closed sense signals from the first contact and the second contact, a duration from when the first contact is closed until the second contact is closed is counted as a first count value and then a duration after this counting has ended is counted as a second count value. An attainment duration value and the second count value are compared, and when a predetermined condition is satisfied, a control signal is outputted. When this control signal is received, sound emission information instructing an emission of a sound by a sound emission controller is sent. The sound emission information includes touch information based on the first count value.