tredjekvartsoktavband

A tredjekvartsoktavband, often abbreviated as 3/4 octave band or third-octave band, is a type of audio filter commonly used in signal processing and acoustics. It represents a subdivision of the audible frequency spectrum. Unlike octave bands which divide frequencies by a factor of two, third-octave bands divide the spectrum into narrower segments. Specifically, a third-octave band has a bandwidth that is approximately one-third of an octave. This means the upper frequency limit of a band is approximately the cube root of two (around 1.26) times the lower frequency limit.

These filters are particularly useful for detailed frequency analysis where finer resolution than octave bands is required. They are frequently employed in applications such as sound level measurements, psychoacoustic studies, and audio equalizers. The human ear's perception of loudness and frequency is often better approximated by third-octave bands than by wider octave bands. This finer resolution allows for a more accurate understanding of how sound is perceived and how it interacts with different environments. The standard for third-octave bands is defined by the International Electrotechnical Commission (IEC) in its standard 61260.