Dual Tone Emergency Whistle

thingiverse

I've tried a lot of whistles, including the famous V2 that's supposed to be really loud. However, I found that a high pitch isn't always audible from far away or in a noisy environment. But what really got on my nerves was that almost all the whistles required a huge blow to produce any decent sound. If this were an actual emergency situation, it might become a problem. My whistle uses two tones: one low and one high pitched. Even with just a little air, there's already some noise, and if you blow hard, it gets pretty loud too. I'm not making any claims about the decibels it can reach since destroying my eardrums wasn't part of the testing, but it should be loud enough! The two tones are closely matched in their harmonics, so when you blow hard, the resulting sound is quite annoying - but still audible from a distance.