I recently purchased a new “golf cart” (actually a low speed vehicle for transportation, not golf). It is kind of fun to drive around in, fun for us oldsters and grandchildren alike. However, the first thing that I noticed is that it comes with an absolutely obnoxious, and unnecessary, back up alarm like you hear on construction sites. It is really, really load – totally ruining the quiet riding experience for me and anyone in the neighborhood.

Because it is so obnoxious I decided to disable it. That sounds easy enough, it must have a couple of wires that can be disconnected – assuming you can find the speaker. So I went on a hunt for a very load speaker on a very small vehicle. This was far from easy because I could not determine where the noise was coming from, there was no directional cues whatsoever. I couldn’t tell which end of the cart it was coming from, couldn’t even tell if it was from the overhead canopy or perhaps under the vehicle.

I thought I must be getting really bad hearing, so I asked my wife to come listen to it and help me know which end of the cart I should be looking to find it. She had no clue either. Others tried to help, but nobody could just distance or direction. I finally looked it up on the internet and found that it was under the passenger seat. As I expected, it was simple to unplug it to shut it up.

However, as a safety engineer this made me really wonder about all of those backup alarms used on construction sites and elsewhere. It appears that the particular sound frequency and volume that they selected for this function makes many (perhaps all?) people unable to judge distance or direction, meaning while they can hear that there is a danger somewhere in the vicinity, they can’t judge whether or not THEY are in danger. Given that there are often many alarms going on at the same time, and that all of the alarms sound the same, I am pretty certain that they just get ignored. They irritate, but my guess is that they don’t do much good as “safety devices”. I suspect that they become just another annoyance to be ignored.

I have seen some advances where people ware warning devices that tell them when they are in a danger zone – specifically for them, and specifically when there is actually danger near by. This sounds much better, but I don’t know enough about the details to be able to judge. Mainly I was just surprised how difficult it was to track the direction of that alarm – clearly it has something to do with the way that the human ear works. Figuring out how to make jobs safer is MUCH more difficult than it seems like it would be because there are so many of these kinds of unexpected situations. Testing in laboratory and field use is key, and those tests have to actually test safety – not the functioning of device that is assumed to be safer.