Recently, ultrasonic waves had been introduced as the transmission medium in Body Area Networks (BANs) to reduce the incalculable damage caused by radio waves. However, the communications based on ultrasonic waves suffer from poor propagation of signals in air and consume too much energy. To address these limitations, firstly, we make the theoretical analysis to ensure ultrasonic waves could be used in BANs (UBANs). Then, we propose an error control strategy in UBANs to dynamically adjust the error control scheme and the Max-Retries based on the current channel state, which is called UECS. The UECS is based on IEEE 802.15.6 standards and considering the characteristics of ultrasonic waves in BANs. Simulation results show that UECS achieves better performance in terms of packet delivery ratio and energy consumption compared with the traditional strategies.