Brainstorm or Green Needle?

We’ve talked before about how our perception isn’t always an accurate representation of the world, and this video is a perfect example of that. Press play, focus on the word “Brainstorm” or the words “Green needle”, and the the audio will seem to say the one you’re focusing on.

After a little practice I was able to switch between the two at will while others only seem to be a able to hear one. How did you get on?