csh {seewave}R Documentation

Continuous spectral entropy

Description

This function computes the continuous spectral entropy (H) of a time wave.

Usage

csh(wave, f, wl = 512, wn = "hanning", ovlp = 0, threshold = NULL,
plot = TRUE, xlab = "Times (s)", ylab = "Spectral Entropy",
ylim = c(0, 1.1), type = "l", ...)

Arguments

wave data describing a time wave or a Sample object generated loading a wav file with loadSample (package sound).
f sampling frequency of wave (in Hz). Does not need to be specified if wave is a Sample object.
wl if at is not null, length of the window for the analysis (even number of points, by default = 512).
wn window name, see ftwindow (by default "hanning").
ovlp overlap between two successive windows (in %).
threshold amplitude threshold for signal detection (in %).
plot logical, if TRUE plots the spectral entropy against time (by default TRUE).
xlab title of the x axis.
ylab title of the y axis.
ylim the range of y values.
type if plot is TRUE, type of plot that should be drawn. See plot for details (by default "l" for lines).
... other plot graphical parameters.

Details

See sh for computing method.

Value

When plot is FALSE, csh returns a two-column matrix, the first column being time in seconds (x-axis) and the second column being the spectral entropy (y-axis) computed along time.
NA corresponds to pause sections in wave (see threshold).

Note

The spectral entropy of a noisy signal will tend towards 1 whereas the spectral entropy of a pure tone signal will tend towards 0.

Author(s)

Jerome Sueur sueur@mnhn.fr

References

Toh, A. M., Togneri, R. & Nordholm, S. 2005 Spectral entropy as speech features for speech recognition. Proceedings of PEECS, pp. 60-65.

See Also

sh, th

Examples

data(orni)
csh(orni,f=22050,wl=512,ovlp=50)
# using the threshold argument can lead to some edge effets
# here sh=1 at the end of echemes
csh(orni,f=22050,wl=512,ovlp=50,threshold=5)

[Package seewave version 1.5.0 Index]