You will use the whistles in practice for setting the beat, when working with children and youth, but especially with your team of warriors in training. I confess that I started making them for this very purpose. (I can also confirm from experience that an antler whistle does not stick to the lips like a regular metal one.)
There is a bit of art and a lot of trial and error involved in making a whistle whistle.
In the past, such whistles made from deer antlers have indeed been found, I attach a picture of an 8th-9th century whistle from Öland, Sweden. The decoration is my own design inspired by Viking drawings and patterns.
Use them to summon people to mount, to signal at games, to summon help in nature or to practice morse code.
Size around 8 cm.
A whistle that can save your life. In case of need for help, calling even for several hours is very debilitating. A little wind is enough and the call is not heard. Whistles can be heard very far away.
International signal code: One whistle: "Where are you?" Two whistles: "Come to me!" Three whistles: "I need help!"
If you hear any of these signals, respond with one whistle. Whistles are at least 3s long.