:Mind you, I wrote "it sounds like", not "it is a". It was a description of the noise, not of the  object itself. – This noise consists of four equal strokes. In my opinion, these equal strokes come neither from a real kick-start nor from a real door. Perhaps we two at least agree that the noise is supposed to symbolize a "goodbye" (in an agressive way). – Anyway, this is all original research and therefore deleted on Wikipedia. Thank you for sharing your thoughts. Cheers