I have thought about getting one years ago. You know those little background chines that you hear on commercials, website or when you turn on electronics.
AOL had one whether it was planned or not had one, the static and dialing when you used to log on. Whenever you were when you heard it you knew someone was using AOL. T-Mobile and Windows have theirs when you turn on their devices.
TV shows have their theme songs or snippets now. But you hear them you remember them almost instinctively.
I consider the audio logo as same as the jingles of old, they are there, you are forced to experience them, and then you can never forget them, like ear worms.
The closest I come is my on-hold music. I have had people tell their friends to call my office just to be put on hold, so they can hear R2D2 talk. I had my tech guy use it as a joke and never changed it. He was in an R2D2 builder group and had the entire stream of R2 speak. So, I had him load it.
Have you every though of using one?