My dad Rodney Shirley does this without fingers and it is the most ear piercing whistle I've ever heard spent many years trying to learn it never could
How to whistle loudly with your fingers - It's a lost art but it could be a life saver - Outdoor Revival
What do you do if you need to catch the attention of someone in the wilderness; shout at the top of your voice, or you can whistle really loud. Whistling houtdoorrevival.com Dorris Wedding beaded wedding wears with covered with bling