Asexperia
Registered Senior Member
It most certainly can and IS. A prime example for people like yourself would be this: The sound coming from a radio is an AC current. And how would you suppose we can increase the volume of that sound without amplifying it? In fact, there are many stages of AC amplification in such communication devices beginning with the initial detection stage that receives the signal from the antenna.
I know what you mean, but the audio signal is a variation of DC.