My keychain whistles are the flat FOX jobs. Hardly perfect, but I bought a fistful on clearance, they're very durable, and they're not bulky.

(The ACR has been favourably mentioned here before. I haven't had a chance to test one -- I guess I'll need to scrounge one online. They're not in the stores up here.)

The second I go afield, I upgrade to the FOX Sharx. These dudes are LOUD, and not unmanageably large. The somewhat lower frequency travels farther IME. My only gripe is the fact that the blast is directed sideways instead of forward. If I had to toot one of these for a long time, I would be half deaf -- I wouldn't notice the SAR helicopter hovering above except for the wash.

The gold star goes to the Storms, which always go in key kits, but they're so darn big. The sound projects forward a bit more, I find. It's also friendly to lower-powered blasts, which brings back the hounds without making my ears ring more than necessary.

From what I've read in other studies, lower pitched whistles with distinctive trills have the best performance across wooded terrain. But, they tend to get lost in noisy environs.

The urban SAR folks seem to prefer the high pitched referees' whistles. Probably for their ability to cut through background noise.



Imagine playing a brass instrument with a large mouthpiece and a wide bore. Something along the lines of a bass trombone or tuba. You don't need a lot of air pressure, but you need a high volume of air to play it. At fortesisimo (triple forte), you may only have 3 seconds or air in your lungs. That's what "too easy" refers to.

Conversely, "too hard" refers to needing high air pressure, but very little air volume. Something like a pocket trumpet or a clarinet. You're carrying 10-20 seconds of air, but you're going to herniate yourself at full blast.

Okay, I understand your example, but the Sharx is hardly a tuba. It's easy to blow and loud, that seems like not "too easy", rather just a good whistle IMO.

As for the ability to cut through background noise, the repetitive pulsing helps. It doesn't sound natural in either environment. But that's just personal opinion, no testing on my part to back it up.

If you cannot blow pump


I'm surprised the tinder whistle wasn't tested


Also interesting, in
brian greens safety whistle testing, Harbor Freight Lightweight Aluminum Whistle came out on top, its now only $1.29

My everyday carry is the Acme 560. To round out my options on a hike, I might add the Acme 649 or the Tops, which have relatively deep tones. I have the Storm. It is my overall "loudest" whistle, but it never gets carried because it is so big. I own about 20 other whistle models.

Although people want to simplify a whistle down to decibels, the perceived loudness of a whistle is very subjective. Loudness is often vastly different to the person blowing the whistle compared to people listening from a distance. Whatever you hear from zero feet away is irrelevant. The deeper tones will sound soft up close, but will carry farther in the wilderness. Do you care more about being heard from 20 meters away or from 1,000 meters away? Also, many older folks cannot hear the higher pitches.

I did my own testing with whistles of various pitches at distances of 400 meters and more. I was surprised by the results. By the way, I tested ease-of-blow by allowing my 2-year-older to try. She could not make a sound with some whistles, a few of them being popular models. I find myself not carrying those whistles. I cannot get the image out of my head of her stuggling with those whistles, while blowing other whistles easily.

This is a practical, simple, cheap experiment for a student to do for science day or whatever they call it nowadays. The student could get rather technical in the theory if need be.

My 3 year olds can get most conventional size pea and cylinder whistles to sing. But the very small (i.e. zipper pull) and very large (lifejacket and storm) are still beyond them. Their biggest problem seems to be the concept of a hard blow to start the whistle, and not covering the fipple with their lips.

My 2 yo daughter did not have a problem with the Storm after I removed her finger from blocking the exit. She could not make a sound with any of my Fox40 (Classic, Sonik Blast, Sharx). She could make a sound with Acme 636. She could make a loud sound with Acme 560. She can make the Acme 660 go the loudest out of all the whistles I own. That little, boring-looking whistle is a powerhouse.