The Science of Sound
This is the term for the scientific study of sound, including its production, transmission, and effects.
Acoustics
This is the term for the sounds produced by living organisms in a given environment, such as birdsong, insect calls, and frog choruses.
Biophony
Bats and dolphins navigate and hunt using this sound-based technique, emitting calls and listening for the returning echoes.
Echolocation (or biosonar)
This broad category of unwanted or harmful sound in the environment, increasingly recognized as a public health issue, is the subject of growing concern.
Noise pollution
Sound travels as this type of wave, where particles move back and forth in the same direction the wave is moving.
Longitudinal (compression) wave
This is the largest animal ever to have lived on Earth. Its calls reach up to 188 decibels and can be heard hundreds of miles underwater — making it one of the loudest animals on the planet.
The blue whale
This small insect produces its distinctive chirping sound by rubbing its wings or legs together — a process called stridulation.
Cricket (also accept grasshopper)
Research has shown that songbirds in urban areas have adapted by shifting their songs in this direction — to be heard above low-frequency traffic noise.
Higher frequencies / higher pitch
Sound travels fastest through this state of matter — solid, liquid, or gas.
Solid
Thunder is the sound produced by this atmospheric phenomenon rapidly heating surrounding air and causing it to expand.
Lightning
Male humpback whales are known for producing elaborate, ever-changing sequences of this, lasting up to 20 minutes.
Songs (humpback whale songs)
This practice, where researchers record natural soundscapes over years or decades to track environmental health and biodiversity changes, is known by this name.
Acoustic monitoring
This unit, named after a Scottish-born inventor, measures the intensity of sound on a logarithmic scale.
Decibel (named after Alexander Graham Bell)
Bernie Krause and his colleague Stuart Gage coined this term for the non-biological natural sounds in an environment — wind, rain, water, and earth movements.
Geophony
Elephants communicate across vast distances using sounds below the range of human hearing, known as this.
Infrasound
The enforced quiet of global lockdowns in 2020 led scientists to observe a phenomenon they called the "anthropause" — during which reduced ocean noise levels visibly affected the behavior of these marine mammals that rely on sound for communication.
Whales (cetaceans)
This phenomenon occurs when a sound source moves toward or away from a listener, causing a perceived change in pitch — famously heard as an ambulance passes by.
The Doppler Effect
Researchers discovered that plants under drought stress emit this type of high-frequency sound, inaudible to humans, from their stems and leaves.
Ultrasonic clicks / ultrasound
This scientific field — pioneered by Bernie Krause and ecologist Stuart Gage through a 2001 research project in Sequoia National Park — studies how the health of a habitat can be measured through its soundscape. R. Murray Schafer's earlier concept of "soundscape" laid the broader foundation.
Soundscape ecology
The International Maritime Organization adopted these voluntary guidelines, aimed at reducing underwater noise from commercial shipping, in response to documented harm to marine life communication — particularly for whales and dolphins that depend on sound to navigate and socialize.
IMO Guidelines for the Reduction of Underwater Noise from Commercial Shipping (adopted 2014)