Whistles as Language

I had an epiphany the other day while watching my Nationals Finals Sheepdog DVD. Diana, called out from the bedroom, asking if those damn whistle noises drove me crazy. Without thinking I replied no because they were like a language to me instead of just noises. Then it dawned - they are becoming like a language and even other people's whistles make more sense to me than just random noises. Now if I could just speak the language more consistently.