A voice circuit is arranged on a chassis member. The voice circuit comprises a voice output amplifier and a high-frequency bypass unit. An output terminal of the voice output amplifier is connected to one end of a voice coil in a speaker through an interconnection, and is grounded through a high-frequency bypass unit. The voice output amplifier supplies a voice current to the voice coil through an interconnection. The resonance frequency of the high-frequency bypass unit is set to the same frequency as that of a discharge current flowing in the chassis member. A high-frequency induced current generated in the voice circuit due to the discharge current flowing in the chassis member flows to a ground terminal through the high-frequency bypass unit.