the encoders in the telephone converts sound energy into electrical energy
sound is energy. telecom is communicating_using_device. electrical_power_generation is energy_conversion_process. voltage_converter is electrical_device. telephone_number_signal_generator is not electrical_component. power_pack is electrical_converter. telephone_number_signal_generator is electrical_component. generator is electronic_device. electrical_power_generation is not energy_conversion_process.