Diaphragm: Found in both the receiver and the microphone; it vibrates to convert sound waves into electrical signals in the microphone and back into sound in the receiver. Soft iron pole pieces: Used in microphones to direct the magnetic field, but not found in the receiver. Permanent magnet: Present in the receiver, where it converts electrical signals back into sound, but not found in carbon microphones. Carbon blocks: These are used in carbon microphones to convert sound into electrical signals; they are not found in the receiver. In a telephone handset, the following components are found in the receiver but not in the microphone: ii. Soft iron pole pieces iii. Permanent magnet