I have spent decades making field recordings in which I create a setup before dawn or dusk, then lie on the ground listening for several uninterrupted hours. These projects have taught me how the density of the air changes as the sun rises or sets, how animal behavior shifts as a result, and how all of these things are intricately linked.

For example, sound travels further through denser material, such as cold air, than through warm summer air. Other factors, such as changes in a forest’s foliage density from spring to fall, also change a site’s reverberation characteristics. Exploring these qualities has led me to think about how perceptual measures of sound inform our understanding of environmental health, opening a new angle of inquiry around psychoacoustic properties of environmental sound.

Reduced plant density will change the balance between absorptive surfaces, such as leaves, and reflective surfaces such as rocks and buildings. This will increase reverberation and make sound environments more harsh. In settings where sound reverberates for a long time, such as a cathedral, it can become tiring to carry on a conversation as echoes interfere. Increasing reverberation could have a similar effect in natural settings.