[SuppressMessage("ReSharper", "SuggestVarOrType_SimpleTypes")] //because ReSharper doesn't like this method private void SetVolume(decimal number) //unmutes the speakers and sets the volume { //installed NuGet AudioSwitcher.AudioApi.CoreAudio 3.0.0.1 for this method CoreAudioDevice speakers = new CoreAudioController().DefaultPlaybackDevice; if (speakers.IsMuted) { speakers.ToggleMute(); //there's no muting this program } speakers.Volume = (double)number; //so that's what casting is... handy }