If you work sheep at a distance, in bad weather or under noisy conditions, you need to use a shepherd's whistle, because the sound of the whistle carries much further than the human voice. Using a whistle enables the dog to hear our commands from farther away.
Unfortunately though, many people find sheepdog whistles difficult to blow.
In this tutorial, Andy describes his favourite whistles and those he avoids, before going on to clearly demonstrate how to get sound from the sheepdog whistle. He also gives examples of typical whistle commands.