Talk about a stupid human trick. This girl can actually talk and sing without opening her mouth. Here she is singing "You Are My Sunshine" without opening her mouth at all! This is one of the latest YouTube videos to go viral. Amazingly, you are able to clearly hear every muffled word of the 1940 classic.

The video, entitled 'The Closed Mouth Singer', has notched up nearly 5.7 million views on YouTube. Enjoy !