<text>  Putting on silly voices is just one of the things adults do to bring a smile to a babys face. And whats better than helium for distorting your voice to make you sound like a friendly chipmunk? Well, for baby Lincoln, the answer appears to be anything. Filmed sitting on what seems to be his mothers lap, Lincoln, who appears to be from America, is joined by his uncle Carson, who holds a purple balloon. After inhaling the helium, Carson says: Hey Lincoln, how are you? in a sinister high-pitched voice while looking at his nephew. Reacting in shock to the sudden change in his uncles voice, Lincoln immediately looks stunned and his bottom lip begins to tremble. As his uncle starts giggling like a chipmunk it all becomes too much for baby Lincoln and he bursts into tears. So far so good: Lincoln sits on what appears to be his mothers lap while his uncle inhales helium from a purple balloon . Responding sympathetically, the youngsters uncle says: Oh no, no, but his high-pitched voice only makes things worse. Eventually, Lincoln is lifted away from his uncle, who laughs apologetically. Helium makes your voice sound high-pitched because it is lighter than air and sound waves can travel through it faster. When inhaling helium, the type of gas molecules in the vocal tract change and increase the voices speed of the sound, making it squeaky. Not impressed: Uncle Carson speaks to his nephew in a high-pitched voice that makes the youngsters bottom lip tremble . Oh dear: Baby Lincoln starts crying and is swiftly lifted away from his uncle who laughs apologetically . 