MH ballast

Hello,
Can anyone tell me how much noise I should expect from a core and coil
MH ballast? I was thinking electronic because of increased
efficiencies, lamp life etc... but from what I've read it seems that
there really isn't that much benefit to the electronic ballast.
Except maybe for noise. The ballast will only be about 3 or 4 feet
away from the sofa and any hum will drive me crazy.

So, are the magnetic ballasts really that noisy?

Thanks,
Erik