When I imagine a huge cannon (like the one in The Pride and the Passion (starring Frank Sinatra and Cary Grant) I imagine the noise it makes is something like "BOOM". It’s certainly a single syllable kind of sound. I imagine the same kind of noise for nearly all explosion-type events.

So where do we get the word “KA-BOOM” from? Does it come from a real life phenomenon? Is there a kind of two syllable explosion which happens in some situations?

Also, why is “KA-BOOM” so obviously bigger than "BOOM"? Why does that extra syllable give it so much extra umph?

I’m thinking that maybe it’s the equivalent of that momentary recoil that cartoon characters do before actions sometimes. Something entirely fictional which none the less seems to emphasise the following action?