Electric cars - silence is deadly?

in that case, I've seen loads of them, they aren't a problem.

I disagree, since I had a crash with another cyclist (who was relying on his sense of hearing to warn him of vehicles behind him) I think to rely on sound at all is dangerous.

Always look... look, look and look again.

I'd say it was the less experienced cyclists who reply on their hearing at all.

Totally disagree, sound is crucial. Relying solely on sound, unless you're a bat, is not a good idea but equally we have forward facing binocular vision and cannot see everywhere at once. Sounds alert to things that happen outside the field of view.