Hi - I am trying to build an electrical system where I generate that electrical 'hum' noise. I plan on the current changing and as a result the amount of 'hum' increases or reduces as well. Ideally, if possible, it would physically vibrate as well. Do you have any idea how I might achieve this? All I can find online is suggestions for reducing this. Thank you!

Well let's see, is this a homework assignment?

Hint, tone generator.