An elevator motion alert system is configured to alert a person of an object moving in at least one hoistway of an elevator system. The elevator motion alert system includes a sensor configured to detect object motion. A transmitter of the elevator motion alert system is carried by the object and is configured to transmit a pressure wave at a pre-defined frequency upon movement of the object. An electronic device of the elevator motion alert system is configured to receive and process the pressure wave for alerting the person of object movement.