That us really cool. And I wouldn't gave even thought of it unless you pointed it out but as a visually impared individual I've had experience with having trouble with trucks witness back-up beeps. I hear that beep and depending on the situation it can be unclear where the sound is coming from. But thinking about busses that give off that hydraulic hiss that's similar to the white noise sound Tom mention here, I'm almost always able to pick out which vehicle that sound came from, unlike the beep. Like I said, I hadn't really thought about it until this video, but thinking back, it's true. Very cool. 😃