A method of controlling distributed devices includes configuring the devices to respond to a controlled signal; positioning the devices in an area of interest; and transmitting the controlled signal into the earth. The earth acts as the signal transmission medium. The method may include controlling a signal generator with a controller to transmit the controlled signal. An illustrative controlled signal may have a fixed frequency, a fixed amplitude, a fixed wave form, a modulated frequency, a modulated amplitude, a modulated wave form, and/or a predetermined duration. In aspects, the method may include connecting the signal generator to the earth and transmitting the controlled signal into the earth using the signal generator. Afterwards, the signal generator may be operated to impart seismic energy into the earth. The devices may be used to detect and record seismic energy that has reflected from underground formations.