Ultrasonic transmitting elements in an electroacoustical transceiver transmit acoustic energy to an electroacoustical transponder, which includes ultrasonic receiving elements to convert the acoustic energy into electrical power for the purposes of powering one or more sensors that are electrically coupled to the electroacoustical transponder. The electroacoustical transponder transmits data collected by the sensor(s) back to the electroacoustical transceiver wirelessly, such as through impedance modulation or electromagnetic waves. A feedback control loop can be used to adjust system parameters so that the electroacoustical transponder operates at an impedance minimum. An implementation of the system can be used to collect data in a vehicle, such as the tire air pressure.