Published by Steve Litchfield at 12:10 UTC, February 7th 2006
A. Yes and no! It's quite normal for PDAs and smartphones to emit a slight buzzing noise. There aren't any moving parts but the various electronic systems and oscillators do give off a little audio noise. Chief among these is usually the LCD screen.
On S60 smartphones, you can usually significantly reduce the noise by turning the display up to full brightness (in 'Settings | Display').
If anyone can shed more light on this (in terms of electronics theory), please comment below!