Biophony

Biophony (aka the niche hypothesis or ecological soundscapes) is the collective sound vocal non-human animals create in each given environment. The term, which refers to one of three components of the soundscape (the others include geophony [non-biological natural sound] and anthrophony [human-induced noise]), was coined by Dr. Bernie Krause. The study of natural soundscapes is called soundscape ecology.

The study of biophony falls under the discipline of biophonics that takes into account the collective impact of all sounds emanating from natural biological origins in a given habitat. The realm of study is focused on the intricate relationships – competitive and/or cooperative – between biological sound sources taking into account seasonal variability, weather, and time of day or night, and climate change. It explores new definitions of territory as expressed by biophony, and addresses changes in density, diversity, and richness of animal populations.

Biophony does not have a literal opposite, except, perhaps, for the complete absence of any biological sound in a given biome.

The "niche hypothesis", an early version of the term, biophony, describes an acoustic partitioning process by which non-human animals in particular habitats adjust their vocalizations by frequency and time-shifting, to compensate for background noise created by other vocal creatures and human-induced noise. Thus each species evolves to establish and maintain its own acoustic territory so that its voice is not masked. Notable examples are the changed vocalizations of great tits in noisy urban environments and killer whales in noisy shipping lanes.