aud.decayslope

The decay phase detected using the 'Attacks' option in aud.events can offer some timbral characterizations. One possible way of describing the decay phase consists in estimating its average slope. Values are expressed in the same scale than the original signal, but normalized in time (expressed in seconds).

Flowchart interconnections

aud.decayslope accepts as input data type either:

• event detection curves (resulting from aud.events), already including peaks or not,
• and all the input data accepted by aud.events.

Some options in aud.events can be controlled:

• aud.decayslope(..., 'Filter') uses the 'Filter' method instead of the default 'Spectro'.
  • aud.decayslope(..., 'Down', r) controls the 'Down' option in aud.events.
  • aud.decayslope(..., 'CutOff', f) controls the 'CutOff' option in aud.events.
• aud.decayslope(..., 'Single') toggles on the 'Single' option in aud.events.
• aud.decayslope(..., 'LogCurve') toggles on the 'Log' option in aud.events.
  • aud.decayslope(..., 'MinLog', ml) controls the 'MinLog' option in aud.events.
• aud.decayslope(..., 'Contrast', c) controls the 'Contrast' option in aud.events.
• aud.decayslope(..., 'PreSilence') toggles on the 'PreSilence' option in aud.events.
• aud.decayslope(..., 'PostSilence') toggles on the 'PostSilence' option in aud.events.

aud.decayslope returns several outputs:

• the decay slope itself and
• the event detection curve returned by aud.events, including the detected events and the attack phases.

Options

• aud.decayslope(..., meth) specifies the method for slope estimation. Possible values for meth are:
  • meth = 'Diff' computes the slope as a ratio between the magnitude difference at the beginning and the ending of the decay period, and the corresponding time difference. (Default choice)
  • meth = 'Gauss' computes the average of the slope, weighted by a gaussian curve that emphasizes values at the middle of the decay period (similar to Peeters, 2004).