Sorry to be flippant. There is one big problem with the EU directive about electric cars having to emit a sound. It's called DEAFNESS.
I am deaf, I do wear my Aids but there are those that do not through vanity.
Many years ago, I was the observer, I am glad to say. 999 call so it was a hurry up job through a busy Town centre. My colleague had the blue light and horns sounding. Just as we got to a light controlled crossing, a little old Lady stepped off the pavement. Well, we did miss her!!!! Did not help our blood pressure nor adrenaline levels. On arrival the 999 was a hoax. Begs the question what if???????
She was completely oblivious of anything, so what use these noises.