The strange synthetic sounds heard in the video are sonification of growth data that were measured in three places on a tree (Pinus sylvestris) by the ecophysiologist, Roman Zweifel, from Swiss Federal Institute for Forest, Snow and Landscape Research WSL.

In data sonification, a series of numbers – for example from a measurement – are used to control sounds that are generated with a computer. The growth spurts of the tree control the pitch of sine tones, creating a tonality that is reminiscent of a language, a voice.

WSL researchers also discovered that trees grow especially at night – in the early hours of the morning.

Spring is the beginning of the vegetation phase: the forest awakes with more intense sunlight, the longer days, and the higher temperatures – flowering and growth begin.

The video sounds best with headphones!