seewave (version 1.5.5)

rmam: Remove the amplitude modulations of a time wave

Description

This functions removes the amplitude modulation of a time wave through the Hilbert amplitude envelope.

Usage

rmam(wave, f, plot = FALSE, listen = FALSE, Sample = FALSE, ...)

Arguments

wave

a vector, a matrix (first column), an object of class ts, Sample (left channel), or Wave (left channel).

f

sampling frequency of wave (in Hz). Does not need to be specified if wave is an object of class ts, Sample, or Wave<

plot

logical, if TRUE returns an oscillographic plot of the nwe time wave (by default FALSE).

listen

if TRUE the new sound is played back.

Sample

if TRUE and plot is FALSE returns an object of class Sample

...

other oscillo graphical parameters.

Value

• If plot is FALSE, a new time wave is returned as a one-column matrix or as a Sample object if Sample is TRUE.

Details

The new time wave is obtained by dividing the original time wave by its Hilbert amplitude envelope.

References

Mbu Nyamsi, R. G., Aubin, T. & Br�mond, J. C. 1994 On the extraction of some time dependent parameters of an acoustic signal by means of the analytic signal concept. Its application to animal sound study. Bioacoustics, 5: 187-203.

See Also

hilbert.

Examples

# generate a new sound with amplitude modulation
a<-synth(f=8000, d=1, cf=1500, am=c(50,10))
# remove the amplitude modulation and plot the result
rmam(a,f=8000,plot=TRUE)