ok, your mission should you choose to accept it is to identify the sound!
I am prepared to answer yes/no questions but I will try & avoid providing any clues… So the question is specifically how was the sound created? It was recorded in real time & hasnt been processed or manipulated at all:
I remember when i was a kid they used to have something like this on the radio. (And yes there is a prize, although i haven’t decided what it is yet)