Frequency spectra of sound can be quite complex, containing a substantial amount of information. Those spectra are often too detailed to be used in other areas than research. Therefore it is necessary to reduce information by using band pass filter. All energy of the signal inside a certain frequency range is summarised and represented by one value. Octave filters are an example of those band pass filters.
The effect of octave filters with different center frequencies is demonstrated for a signal consisting of white noise.


 
