seewave (version 2.1.6)

soundscapespec: Soundscape frequency spectrum of a time wave

Description

This function returns a kHz binned spectrum as described by Kasten et al. (2012) for the description of a soundscape.

Usage

soundscapespec(wave, f, channel = 1, wl = 1024, wn = "hamming", ovlp = 50,
plot = TRUE, xlab = "Frequency (kHz)", ylim = c(0, 1), ...)

Arguments

wave

an R object.

f

sampling frequency of wave (in Hz). Does not need to be specified if embedded in wave.

channel

channel of the R object, by default left channel (1).

wl

length of the window for the analysis (even number of points, by default = 1024).

wn

window name, see ftwindow (by default "hamming").

ovlp

overlap between two successive analysis windows (in %), by default = 50%.

plot

if TRUE returns a barplot.

xlab

title of the barplot x axis.

ylim

range of the barplot y axis.

…

other barplot graphical parameters.

Value

A two-column numeric matrix, the first column returning the frequency (kHz) bands and the second column returning the power value within each frequency band. A barplot is returned when plot is TRUE.

Details

The soundscape frequency spectrum is based on the computation of a spectrogram power spectral density using Welch'smethod (Welch & June, 1967). Parameters used in Kasten et al. (2012) were a Hamming window of 1024 samples with 50% of overlap and are used here as default values.

References

Kasten, E.P., Gage, S.H., Fox, J. & Joo, W. (2012). The remote environmental assessment laboratory's acoustic library: an archive for studying soundscape ecology. Ecological Informatics, 12, 50-67. Welch, P.D., June (1967). The use of the fast Fourier transform for the estimation of power spectra: a method based on time-averaging over short, modified periodograms. IEEE Transactions on Audio and Electroacoustics, 15: 70-73.

See Also

spec, meanspec, SAX, NDSI

Examples

# NOT RUN {
## Note that 'tico' is not a soundscape recording...
data(tico)
soundscapespec(tico, plot=TRUE, col="darkgreen")
# }