# spectralDecrease

Spectral decrease for audio signals and auditory spectrograms

## Syntax

## Description

specifies options using one or more name-value arguments.`decrease`

= spectralDecrease(`x`

,`f`

,`Name=Value`

)

`spectralDecrease(___)`

with no output arguments plots
the spectral decrease. You can specify an input combination from any of the previous syntaxes.

If the input is in the time domain, the spectral decrease is plotted against time.

If the input is in the frequency domain, the spectral decrease is plotted against frame number.

## Examples

## Input Arguments

## Output Arguments

## Algorithms

The spectral decrease is calculated as described in [1]:

$$\text{decrease}=\frac{{\displaystyle \sum _{k={b}_{1}+1}^{{b}_{2}}\frac{{s}_{k}-{s}_{{b}_{1}}}{k-1}}}{{\displaystyle \sum _{k={b}_{1}+1}^{{b}_{2}}{s}_{k}}}$$

where

*s*is the spectral value at bin_{k}*k*.*b*_{1}and*b*_{2}are the band edges, in bins, over which to calculate the spectral decrease.

## References

[1] Peeters, G. "A Large Set of Audio Features for Sound Description (Similarity and Classification) in the CUIDADO Project." Technical Report; IRCAM: Paris, France, 2004.

## Extended Capabilities

## Version History

**Introduced in R2019a**