Octaves and 1/n octaves are frequency bands, the width of which increases with the center frequency, to get closer to the human ear perception. The particularity of octave bands is the doubling of the center frequency between two consecutive bands. One octave band contains 3 third octave bands.
The octave analysis is the transformation of a continuous signal into a 1/n octave spectrum using Constant Percentage Bandwidth (CPB) Filters.
The filters are defined with:
- A center frequency fc (according to IEC 61260 standard)
- The cut-off frequencies flow and fup.
Octave analysis is very common for noise measurements (to represent sound pressure and sound power spectra) as well as floor vibration testing.