17 19 hz

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.

Generally, humans cannot consciously perceive infrasound, but they can feel it . In the British study, researchers played music laced with infrasound for test subjects, and 22 percent reported feelings of uneasiness, revulsion, or fear after listening.

Humans can generally sense sounds at frequencies between 20 and 20,000 cycles per second , or hertz (Hz)—although this range shrinks as a person ages. Prolonged exposure to loud noises within the audible range have long been known to cause hearing loss over time.