[upofadown]

My experience:

Unless the internal combustion engine powered vehicle is accelerating or travelling at highway speeds I don't hear the engine. I actually hear the sound of the tires on the road and displaced air. Modern engine/exhaust systems are so quiet that for all practical purposes they are silent.

The only thing I miss with an electric/hybrid vehicle as a pedestrian/cyclist is the reving sound from the engine when a vehicle starts moving without any other warning (not that you can actually hear that in many urban environments). My current opinion is that all larger vehicles should make a noise when they start moving. That might have the nice side effect of making it possible to do away with those stupid backup alarms...