The human ear can generally hear sounds with frequencies between 20 Hz and 20 kHz (the so called “audio range”). 20 Hz is a very low frequency while 20 kHz is a very high frequency. Examples of low frequencies in our surroundings are the bass in music or the low humming that a fan generates. Examples of high frequencies are the treble in music or the high notes of a small child. Both speech and music are a mixture of high to low frequencies.
When sound is made, may it come from human speech or a HiFi speaker, the room is filled with it. And if it is not absorbed then it bounces around until drained of energy. In a room with hard walls this bouncing can go on for quite some time. These echoes, or reverberations, greatly impacts our daily lives – may it be during conversations, HiFi listening or working in an open office environment.