I'm puzzled by how inexact is the reason for changing the type of noise used. The two real reasons based on how the human auditory system works (aka ears) are:<br>1. Broadband noise is masked easier than narrowband tones. Difference is aprox. 10dB or more, so neighbors will be much happier!<br>2. The human ears cannot geo-localize narrowband tones. So using a tone for a reversing beep has always been a bad idea. In audio geek circles we've been complaining for ages!<br>Hope here in the US they will finally understand this