no. that is not true because, you have to think "well what can I clap on one hand for it to make a sound?" or "is my clapping metaphorical as in silent applause?" there are many answers to this but...
We all heard a whistle before, but when you are writing something and you want to type or write a whistle sound, it gets you thinking. If I were writing it i would put, WHEWWW, or, PHEWWWWWW. NO A...