Study: Hand clapping is akin to a Helmholtz resonator

Hand clapping is ubiquitous behavior for humans across time and cultures, serving many different purposes: to signify approval with applause, for instance, or to keep time to music. Acousticians often use a hand clap as a cheap substitute for pricey equipment to make acoustic measurements in architecture. While the basic physical mechanism is simple, the underlying physical mechanisms are less well-understood.
A new paper published in the journal Physical Review Research provides experimental support for the hypothesis that hand clapping essentially acts like a Helmholtz resonator—akin to the hum generated by blowing across the top of a bottle, or the hiss one hears when holding a conch shell to one’s ear.
In 2020, engineers Nikolaos Papadakis and Georgios Stavroulakis, both at the Technical University of Crete, recruited 24 students to clap their hands once in different venues, varying their hand configurations in 11 different ways—changing the angle of the hands with respect to one another, for instance, or changing how many fingers of one hand overlapped with the fingers or palms of the other.