djones51Making the electricity vary between positive and negative at the speed and amplitude of the sound makes the speaker reproduce the sound.
Yes, but that is not what an amplifier does; the audio signal is already varying from positive to negative before it reaches the amplifier. We know that because audio signals are AC. The amplifier simply provides more power for the analog audio signal.
The very definition of analog is what seems to be what’s confusing you:
"being a mechanism or device in which information is represented by continuously variable physical quantities ... something that is similar or comparable to something else either in general or in some specific detail : something that is
analogous to something else."
I’m not sure why you now believe the obviously analog signal is some kind of magical "electrical pulse." You seemed to understand this earlier when you wrote:
Audio signal is electrical waves that represents sound waves in analog
I’m sure you can understand that a wave is not a pulse!