LET'S REMINISCE: The art of whistling
My dad was a very accomplished whistler, and one of my very early memories is of him trying to teach me how to do it. At first I was trying too hard, and once I relaxed it came easily. But I never learned to whistle as well as he could.
I thought about this recently as I read about the 2020 Global Whistling Championship, held late last year by means of video submissions. It was sponsored by the International Whistlers Guild, which promotes the art of whistling as mankind’s oldest and most unique musical expression. Sept. 3 was World Whistling Day.
The basic physics of whistling is surprising. When you whistle, you create a space in your mouth with a hole at each end: one at the back, where the tongue pushes against the roof of your mouth and leaves a small gap, and one at the front, where you purse your lips.
When you exhale, a thin jet of fast moving air whooshes in from the hole at the back. As this travels forward it starts to wobble where it’s pushing past the still air. Its outermost layer bends out and around to form a ring, like a smoke ring without the smoke. Other rings form behind it, creating a well-ordered line.
When these rings hit the front of your mouth, each one generates a pressure wave that is transmitted backward, tweaking the timing of the new rings forming at the back of your mouth. The critical skill in whistling is using your tongue to shape your mouth cavity so that it resonates with those pressure pulses, amplifying them into a single pure tone. That’s the whistle you hear.
It’s quite complex, highlighting just how flexible and skillful is the tongue and mouth control we have. Our tongues are amazing shape-shifters, moving forward to make the mouth space smaller and create high notes, up and backward to increase the space to create the low notes.
The difficulty in learning to whistle is that no one can really explain how to do it, because it all takes place inside our mouths and is therefore invisible. Although we associate whistling with a particular lip shape, lips actually play a very small role. They don’t contribute to the vibration of the air inside your mouth.
Even the scientists who study this are still working out the details, because it’s only recently that MRI scanners have let them see inside the hidden space where the physics happens.
Whistling can reach 120 decibels and travel up to a mile, while shouting doesn’t often get above 100 decibels and carries only 200 yards. This is because the energy of a whistle is concentrated in a single high-pitched note, which is easy to distinguish from background noise. Long before cellphones were invented, some communities in mountainous or heavily forested regions around the world were using whistled language to communicate over long distances.
I enjoyed playing with plastic whistles during my boyhood, and I was not surprised to learn that whistles made of bone or wood have been used for thousands of years.
Whistles were used by the Ancient Greeks to regulate the stroke of galley slaves while rowing. The English used whistles during the Crusades to signal orders to archers. In the 1880s a man named Joseph Hudson developed a brass whistle and convinced Scotland Yard that it would be an aid to police work.
Finally, I remember an old saying to the effect that a whistling woman and a cackling hen will come to no good end. So girls aren’t supposed to whistle?
Jerry Lincecum is a retired Austin College professor who now teaches classes for older adults who want to write their life stories. He welcomes your reminiscences on any subject: firstname.lastname@example.org.