If you have a close look at a tire tread pattern you will notice that the single tread blocks all differ in size.
Nearly every car tire has this property. With the help of simple sound amplification the Physikanten show that the sound of the rotating wheel is clearly different depending on whether you have a normal tire or a specially designed one with equally-sized tread patterns.
How does it work?
Each time a tread block hits the street, a little sound is produced. If all tread blocks had the same size, these sounds would reach our ears at regular intervals as a certain frequency – a tone.
However if the tread blocks all have irregular sizes then you don’t hear a tone but rather a kind of noise, which isn’t pleasant but is less annoying than a distinct tone.
