Is 20 Hz high or low?

The range from 10Hz to 100Hz may be considered as the low frequency region , with a possible extension by an octave at each end. There is no need to consider infrasound as a “special case”. However, audible sounds at the lowest frequencies will be at a high decibel level (Table I).

Especially dangerous is infrasound at the frequency of 7 Hz , since this sound, generating frequencies, close to characteristic frequencies of the organs of our body, may disturb the heart or brain activity. Machines, natural sources storms, earthquakes, hurricanes, etc. generate infrasound.

Sound at 20-200 Hz is called low-frequency sound , while for sound below 20 Hz the term infrasound is used. The hearing becomes gradually less sensitive for decreasing frequency, but despite the general understanding that infrasound is inaudible, humans can perceive infrasound, if the level is sufficiently high.

Frequency is measured in hertz (Hz) [hurts]. A low- frequency sound is about 500 Hz or lower. A high- frequency sound is about 2,000 Hz and higher.