I dont hear it I only hear "Green needle". Then when I focus on the other word, I notice that there is a bit of a "B" sound (almost sounds like "breen"), but I never hear "brainstorm" at all.
I think the trick is that they distort part of both both words a bit, but even so, it did not work for me.
darn! try saying brainstorm 10 times .. then look at only the word brainstorm and see what happens. i guess it doesnt work for everyone.. for me it worked a charm..
Yeah unfortunately I tried it many times but I just didnt sound anything like it for me.
It is definitely more of a "trick" though, they obviously distort the pronunciation of the words.