https://www.sciencedaily.com/releases/2021/01/210125112308.htm

Quantum mechanics tells us that physical objects can have both wave and particle properties. For instance, a single particle -- or quantum -- of light is known as a photon, and, in a similar fashion, a single quantum of sound is known as a phonon, which can be thought of as the smallest unit of sound energy.

A team of researchers spanning Imperial College London, University of Oxford, the Niels Bohr Institute, University of Bath, and the Australian National University have performed an experiment that can add or subtract a single phonon to a high-frequency sound field using interactions with laser light.