infrasonic
/ˌɪnfrəˈsɑnɪk/
adjective
- Relating to sound waves with a frequency below the range of human hearing (below about 20 hertz).
- Elephants use infrasonic calls to communicate over long distances.
- The infrasonic vibrations from the earthquake were detected by special sensors.
- Some animals, like whales, can produce and hear infrasonic sounds.