Science: it’s best done at home in front of your webcam. Case in point: Cody here of Youtube channel Cody’sLab first inhaling dense gas sulfur hexaflouride and talking so we can hear what that sounds like, then inhaling some perfluorobutane (a gas almost twice as dense as sulfur hexaflouride) and talking after that. The result? Scary. Of course I have a naturally deep, booming voice so I don’t need to inhale these sorts of things to sound menacing. “Sometimes I can’t tell if he’s talking or just farted.” Honey! “What?” That might be the sweetest thing you’ve ever said to me.