Infrasonic (adjective)

1. Having a frequency below the range of human hearing (generally less than 20 Hz).
2. Referring to or produced by infrasonic waves.

Origin:

Late 19th century: from in- + sonic.

Examples:

1. Infrasonic sound waves can travel long distances in the atmosphere.
2. The study of infrasonic signals has revealed much about the earth's interior.
3. Infrasonic detectors are used to monitor earthquakes and volcanic activity.
4. Infrasonic recordings of the ocean have provided important insights into whale behavior.
5. Infrasonic signals produced by wind turbines can have negative effects on nearby wildlife.