The companies and the public bodies spend a lot of effort allocating electromagnetic spectrum (frequency) to new wireless technologies. For those that don't know what electromagnetic spectrum is, the easiest way to understand would be the radio station frequencies. All know that two radio stations cannot transmit or be received at the same frequency.
What about the audio spectrum? Sound waves, just like electro-magnetic waves have a frequency. The beautiful process of evolution has provided the millions of species that are competing for audio frequencies like radio stations an almost perfect allocation of sound frequencies. As this great article in Wired Magazine explains, if you scan the audio frequencies in a forest, each species have their own. If not their mating calls would be lost, and they would not be able to produce. Pretty straight forward.
Until the humans came up with their machines that produce sound in all the frequencies that you can think of. It looks like there are adversary effects on species that rely on audio signals for mating and danger aversion. We pollute in many different dimensions.
Clive Thompson has spend years recording the soundscapes in different parts of the world. He is referred in the article. He has this great Google Maps overlay, where you can listen to the forests all around the world.