sulfur

http://www.youtube.com/watch?v=5LZ7vystdkA&eurl=http%3A%2F%2Fwww%2Etecheblog%2Ecom%2Findex%2Ephp%2Ftech%2Dgadget%2Fvideo%2Djay%2Dleno%2Dinhales%2Danti%2Dhelium As the guy in the video says, this gas basically acts oppositely compared to helium. Instead of filtering out all the low vocals, it...