Provided are a medium conveying apparatus, a control method, and a control program to enable more accurate detennination whether a medium conveyance abnormality has occurred. A medium conveying apparatus includes an ultrasonic transmitter capable of outputting an ultrasonic wave, an ultrasonic receiver opposed to the ultrasonic transmitter, to receive the ultrasonic wave and output an ultrasonic signal corresponding to the received ultrasonic wave, a pressure detection module to detect atmospheric pressure, based on the ultrasonic signal, a sound receiver to receive a sound and generate a sound signal corresponding to the received sound, an abnormality determination module to determine whether a medium conveyance abnormality has occurred, based on the sound signal, and a modification module to modify sensitivity of the sound receiver, correct the sound signal, or modify a criterion for determination of a medium conveyance abnormality by the abnormality determination module, based on the atmospheric pressure.