The Audio Amplifier
Once the audio has been recovered by the detector, it passes to the
audio stages of the receiver. Depending upon the quality of the receiver, the
audio will be boosted and further adjusted with tone and volume controls before emerging
into the world once again through the loudspeaker!
The picture shows that it's easy to spot the audio stages in a receiver. The low frequency audio needs big capacitors and big coils - and the appearance of the loudspeaker is familiar to most of us.
And that's how radio works!