This is the "alert sound" I've had set on my mac for years now. I wanted something that was quick, easy to hear, emotionally neutral, and at least kind of pleasant if you have to hear it a lot. None of the built-in sounds fulfilled all of these requirements and most of them fail at most, so I designed my own. If you want to use it, drop it into ~/Library/Sounds, making that folder if it doesn't already exist.
I don't remember why the file is seven seconds long, but it's probably fine.