Inhaling helium causes the human voice to sound incredibly high-pitched because sound travels nearly three times faster through helium than it does through normal air.

A closer look

Inhaling helium causes the human voice to sound incredibly high-pitched because sound travels nearly three times faster through helium than it does through normal air. This rapid speed changes the resonant frequencies of the human vocal tract, amplifying the higher-pitched sounds and creating that classic cartoon chipmunk effect. People completely waste this finite, non-renewable element, which is crucial for cooling MRI machines and operating particle accelerators, just to make funny voices at toddler birthday parties. We are literally depleting the universe's second most abundant element from our planet's crust so Uncle Dave can do a mediocre impression of a munchkin. Future generations will look back at our medical crises and realize we sacrificed critical life-saving technology for some cheap laughs and floating metallic balloons!