A similar confusion may be audible in any McDonalds.
Their kitchens have many alerts and alarms, and many of them
use the same tone. Get a beverage, stand with a view
behind the counter toward the kitchen, wait, and listen.
Back in the 80's people would make intelligible speech simply by connecting a speaker to a 5V 1-bit I/O port. So there's no excuse from a cost standpoint.