A transport apparatus includes a speaker and a mike disposed at respective positions between which a transport path of a medium is interposed, where the speaker and the mike face each other, a drive circuit that outputs a drive signal to the speaker, an amplifier circuit formed by coupling a plurality of amplifiers in series, where the amplifier circuit amplifies and outputs an output signal of the mike, a processor to which the output signal of the amplifier circuit is input, an attenuation circuit disposed in a stage preceding a predetermined amplifier, where the attenuation circuit attenuates an input signal and outputs the input signal to the predetermined amplifier, and a switch that switches an attenuation factor by the attenuation circuit.

A transport apparatus includes a speaker and a mike disposed at respective positions between which a transport path of a medium is interposed, where the speaker and the mike face each other, a drive circuit that outputs a drive signal to the speaker, an amplifier circuit formed by coupling a plurality of amplifiers in series, where the amplifier circuit amplifies and outputs an output signal of the mike, a processor to which the output signal of the amplifier circuit is input, an attenuation circuit disposed in a stage preceding a predetermined amplifier, where the attenuation circuit attenuates an input signal and outputs the input signal to the predetermined amplifier, and a switch that switches an attenuation factor by the attenuation circuit.

A post-processing apparatus includes a blade, a transfer mechanism, a sheet folding roller pair, a motor, a drive control device, and a control device. The blade presses into the sheet to form a fold line in the sheet. The transfer mechanism moves the blade toward and away from the sheet. The sheet folding roller pair conveys the sheet with the fold line formed by the blade by pinching the sheet at a nip between the sheet folding roller pair. The motor rotatively drives the sheet folding roller pair. The drive control device controls drive of the motor. The control includes a control circuit. When, through the processor executing a control program, the control device controls the transfer mechanism to withdraw from the nip the blade having been pressed into the sheet and the nip by the transfer mechanism, the control device controls the drive control device to stop the motor.

A post-processing apparatus includes a blade, a transfer mechanism, a sheet folding roller pair, a motor, a drive control device, and a control device. The blade presses into the sheet to form a fold line in the sheet. The transfer mechanism moves the blade toward and away from the sheet. The sheet folding roller pair conveys the sheet with the fold line formed by the blade by pinching the sheet at a nip between the sheet folding roller pair. The motor rotatively drives the sheet folding roller pair. The drive control device controls drive of the motor. The control includes a control circuit. When, through the processor executing a control program, the control device controls the transfer mechanism to withdraw from the nip the blade having been pressed into the sheet and the nip by the transfer mechanism, the control device controls the drive control device to stop the motor.