AVAS

Can anyone describe the sound the Acoustic Vehicle Alert System (AVAS) emits? It's such a weird noise that I just cannot think of a way to describe the noise. My 7 year old son says it sounds like an elevator, to me it's like they have recorded the sound of a vacuum cleaner. The easiest way to hear it is to start the car and put it in neutral (leaving the handbrake on!), pressing the brake will lower the volume until it is silenced and releasing the brake will increase the volume.

Wee John.

I'd call it an electronic resonant humming, something UFO-like, more modern than the Jetson's car, but never to be confused for infernal combution! My kids say it goes woo-woo-woo.