An implantable stimulation system comprises an implantable stimulator and a control device. The control device is configured to transmit acoustic waves to the implantable stimulator, and the implantable stimulator is configured to transform the acoustic waves into electrical current, and generate stimulation energy based on the electrical current. For example, the electrical current can be transformed into electrical energy that can be used to generate the stimulation energy. Or the electrical current can contain signals used to directly or indirectly control the generation of the stimulation energy.