The purpose of the filter bank is to divide the audio signal into 32 equal-width frequency subbands. Empirical evidence has shown that the human ear has a limited resolution that can be expressed in terms of critical bandwidths less than 100Hz and more than 4kHz. Within a critical bandwidth the human ear blurs frequencies. Thus the filter bank creates equal-width frequency subbands that correlate to the critical bandwidths in a method diagrammed in the following figure.