i really like my dogs do you have any dogs ?
I really like them too. I have one german shepherd, he's really domestic
thats nice, what is his name i use to have a german shepherd as well they are great dogs 
His name is max, we use him a lot when herding the animals on the farm, no sheep but the cattle listen to him
Cool, how long have you had him then and did you train him up ?
we have had him for 3 years, it takes a lot of training to get a dog to act on the sound of a whistle so now that he listens its awesome. 
yea, ive tried that with my dog and it didnt work she just wont listen to it, are you a farmer then ?
Physics of whistles
A whistle is a device that makes sound from blowing air. The physical theory of the sound making process is an example of the application of the science of fluid dynamics. Knowledge of the geometry, dimensions and fluid properties can allow prediction of the properties of the whistle. The principles relevant to whistle operation also have applications in other areas such as fluid flow measurement.
Types.
Wilson, et al., in their study of human whistling (see below), pointed out the importance of
seven other dogs in the final round including a German Shepherd Dog, a Borzoi and a Pekingese. Best in Show judge Barbara Heller said of Robert's victory, "The dog is as near to perfection as possible, He showed his heart out and I had a really hard time deciding. I always think it's easy to judge when you have good dogs, but this time it wasn't that easy because all seven were outstanding." He became the first English Springer Spaniel to take the title since 1972.