Hertz sound

However, a 20 Hz sound with about a 120 dB intensity level sounds equally as loud as a 3 kHz sound with about a 110 dB intensity level .

Sound at 20-200 Hz is called low-frequency sound , while for sound below 20 Hz the term infrasound is used.

Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound.

Hertz are units used to measure frequency. One hertz is defined as one cycle per second. So, a frequency measured at 20 Hz is traveling at 20 cycles (or waves) per second .5 Eyl 2018