The "sssss" noise/syllable is easy to make and can be made continuously. The detector emits an event
1 when you start saying "sss" and a
2 after you stop. It's good to hook up to variable-length actions like clicking/dragging and scrolling. It can detect very quiet noises so even just barely saying "ssss" under your breath should trigger it without annoying anybody else around you too much. It works with most "sss" syllables but I find sharper is better, in crispness that is, loudness doesn't matter much. It has a very low false negative rate, but often has false positives. It will obviously trigger in english speech since "s" is a common syllable, but with some microphones breathing in certain ways will trigger it as well. Personally I use this to scroll down, it allows me to read long articles and books lying down with my laptop without awkward hand positioning to scroll with the trackpad.