There are provided a paper conveying apparatus, a jam detection method and a computer-readable, non-transitory medium which can determine whether a jam has occurred based on the sound which is generated by a paper during conveyance at a low cost. The paper conveying apparatus includes an ultrasonic detector, provided near a conveyance path of a paper, for detecting an ultrasonic wave which passes through paper and outputting an ultrasonic signal, a multifeed detector for determining whether multifeed of papers has occurred based on a component of a first frequency band in the ultrasonic signal, and a sound jam detector for determining whether a jam has occurred based on a component of a second frequency band lower than the first frequency band in the ultrasonic signal.