I'm not sure, cannot remember, but I sat on an electric motorcycle in Roger's AR Indian dealership. It had a shift lever on the left with a brake pedal on the right. Not sure now if it had a clutch lever or not. So that "may" be an electric with a trans.
As far as the HD Livewire, I'm not sure, but I believe the electric motor is mounted longitudinally within the frame. This would require a 90 degree gearbox for the motor input and the drive belt output. Most 90 degree gearboxes have a bit of a whine to them, unless they're hypoid geared.
I too heard the decel gear noise in the HD video, so it's not completely quiet. Maybe they have a v-twin soundtrack and speakers to go with the throttle? Or maybe they have playing cards in the spokes...