Question

What are infrasonics?​

Answer 1

Infrasonics...relating to or denoting sound waves with a frequency below the lower limit of human audibility.

Answer 2

Infrasonics, vibrational or stress waves in elastic media, having a frequency below those of sound waves that can be detected by the human ear—i.e., below 20 hertz. The range of frequencies extends down to geologic vibrations that complete one cycle in 100 seconds or longer.