Envelope Detector Improvements?
Impulse noise is demodulated on an AM radio. Snap, crackle and POP are common sounds.
If you smooth impulse sounds then speech and some music will sound weird.
AM radio does not pass 9kHz sounds, but only 4kHz if you are lucky. Most AM radios cut frequencies above only 2.5kHz, which is why FM radio was made to sound much better.