The noise made by the AVASS Matilda might be expected to be similar to a modern trolley bus, the nearest examples being in Wellington, NZ (but apparently not for much longer). Apparently quietness is not a problem there. The potential issue mainly relates to the silent start as opposed to the diesel engine idling (indicating a 'live' vehicle) and rev up preparatory to getting underway. Once moving, there are various noises such as from the tyres on the road, motor hum, sqeaks/rattles (?), etc. which would not be less than that from a modern quality sedan, so moving electric bus quietness should not be an addition to existing issues. I lived in a trolley bus using city (Hobart) and the silent aspects were then never cited or commented on as a problem, rather it was seen as an advantage.
The point about wandering pedestrians is a real worry. I (not wandering) had a very near miss at Westfield Belconnen that could have been much worse if an electric bus had been involved. Briefly, a bus approaching platform 1 had paused just before the stop line at the light controlled pedestrian crossing to avoid illegal (wandering) crossers. The driver didn't notice the lights changed during the pause and proceeded against the red light. I had just stepped onto the crossing WITH the now displayed 'Walk' sign (and audible signal) when I heard the bus engine revs increase and leapt back out of its path just in the nick of time. ACTION never identified the driver who clearly didn't notice pedestrians now using the crossing. I might not have noticed it in time had it been an electric bus. Nor might the many illegal/wandering crossers making a run for it notice, which will add to the every day problems for the bus drivers.