The trouble is that I know what the beeping sound is, so I know that it means a danger and I look for that danger. But the white noise "alert" sounds like compressed air escaping, so I wouldn't look for any danger at all, or even worse, for the wrong danger.<br><br>I work at a turnpike service plaza, so I'm going through the heavy-truck parking area on a regular basis. I would vehemently oppose a similar shift in my local jurisdiction.,(reply>), +James Paulsen I agree entirely. When ever I hear a beeping I look for a vehicle nearby, to my knowledge, I have never heard the white noise sound on trucks around here, and if I have I must have assumed it was the air brakes, thus being completely oblivious to any danger.