telephone answering machine
Device attached to a telephone that answers calls with a prerecorded message and then records the messages left by callers.
speaker 
Integrated device used to generate sound.
volume control 
microphone 
Device that converts electric pulses into broadcast or recorded sounds.
outgoing announcement cassette 
Cassette containing the greeting for callers.
auto-answer indicator 
power-on light 
Signal light indicating that the answering machine is on.
calls indicator 
Signal light indicating that one or more messages have been received.
incoming message cassette 
Cassettes on which callers’ messages are recorded.