An implantable medical device includes an acoustic transducer for intra-body communication with another medical device via an acoustic couple. The acoustic transducer includes one or more piezoelectric transducers. In one embodiment, an implantable medical device housing contains a cardiac rhythm management (CRM) device and an acoustic communication circuit. The acoustic transducer is electrically connected to the acoustic communication circuit to function as an acoustic coupler and physically fastened to a wall of the implantable housing, directly or via a supporting structure. In one embodiment, the implantable medical device receives an incoming acoustic signal from the other medical device, detects an error rate associated with the incoming acoustic signal, and adjusts a carrier frequency for an outgoing acoustic signal to be transmitted to the other medical device using the error rate.