Which device component converts electrical energy to sound in the receiver?

• A. The microphone.
• B. The earphone.
• C. The loudspeaker.
• D. The transmitter.

Answer: (B)

The receiver’s job is to turn the electrical signal back into audible sound for the listener. The earphone does exactly that: it is a transducer that, when the electrical signal from the line drives its coil and diaphragm, creates sound waves you can hear. The microphone is the sending side, converting sound into electrical energy. The transmitter is about sending signals, not producing sound at the listener’s ear. A loudspeaker could convert electrical energy to sound, but in this Navy sound-powered setup the device worn at the ear for listening is the earphone. So the earphone is the component that converts electrical energy to sound in the receiver.