# FrequencyBands¶

standard mode | Spectral category

## Inputs¶

`spectrum`

(vector_real) - the input spectrum (must be greater than size one)

## Outputs¶

`bands`

(vector_real) - the energy in each band

## Parameters¶

`frequencyBands`

(vector_real, default = [0, 50, 100, 150, 200, 300, 400, 510, 630, 770, 920, 1080, 1270, 1480, 1720, 2000, 2320, 2700, 3150, 3700, 4400, 5300, 6400, 7700, 9500, 12000, 15500, 20500, 27000]) :list of frequency ranges in to which the spectrum is divided (these must be in ascending order and connot contain duplicates)

`sampleRate`

(real ∈ (0, ∞), default = 44100) :the sampling rate of the audio signal [Hz]

## Description¶

This algorithm computes energy in rectangular frequency bands of a spectrum. The bands are non-overlapping. For each band the power-spectrum (mag-squared) is summed.

Parameter “frequencyBands” must contain at least 2 frequencies, they all must be positive and must be ordered ascentdantly, otherwise an exception will be thrown. FrequencyBands is only defined for spectra, which size is greater than 1.

- References:
[1] Frequency Range - Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Frequency_band

[2] Band - Handbook For Acoustic Ecology, http://www.sfu.ca/sonic-studio/handbook/Band.html

## Source code¶

## See also¶

FrequencyBands (streaming)