warbleR (version 1.1.1)

specan: Measure acoustic parameters in batches of sound files

Description

specan measures 22 acoustic parameters on acoustic signals for which the start and end times are provided.

Usage

specan(X, bp = c(0,22), wl = 512, threshold = 15, parallel = 1)

Arguments

X

data frame with the following columns: 1) "sound.files": name of the .wav files, 2) "sel": number of the selections, 3) "start": start time of selections, 4) "end": end time of selections. The ouptut of manualoc

bp

numeric vector of length 2 giving the lower and upper limits of the frequency bandpass filter (in kHz). Default is c(0, 22).

wl

A numeric vector of length 1 specifying the spectrogram window length. Default is 512.

threshold

amplitude threshold (%) for fundamental frequency and dominant frequency detection. Default is 15.

parallel

Numeric. Controls whether parallel computing is applied. It specifies the number of cores to be used. Default is 1 (e.i. no parallel computing). For windows OS the warbleR from github to run parallel.

Value

• Data frame with the following acoustic parameters:
  • duration: length of signal
  • meanfreq: mean frequency (in kHz)
  • sd: standard deviation of frequency
  • median: median frequency (in kHz)
  • Q25: first quantile (in kHz)
  • Q75: third quantile (in kHz)
  • IQR: interquantile range (in kHz)
  • skew: skewness (see note inspecpropdescription)
  • kurt: kurtosis (see note inspecpropdescription)
  • sp.ent: spectral entropy
  • sfm: spectral flatness
  • mode: mode frequency
  • centroid: frequency centroid (seespecprop)
  • peakf: peak frequency (frequency with highest energy)
  • meanfun: average of fundamental frequency measured across acoustic signal
  • minfun: minimum fundamental frequency measured across acoustic signal
  • maxfun: maximum fundamental frequency measured across acoustic signal
  • meandom: average of dominant frequency measured across acoustic signal
  • mindom: minimum of dominant frequency measured across acoustic signal
  • maxdom: maximum of dominant frequency measured across acoustic signal
  • dfrange: range of dominant frequency measured across acoustic signal
  • modindx: modulation index. Calculated as the accumulated absolute difference between adjacent measurements of fundamental frequencies divided by the frequency range

Details

The ouptut of manualoc or autodetec can be used directly without any additional modification. The function measures 22 acoustic parameters on each selection in the data frame. Most parameters are produced internally by specprop, fpeaks, fund, and dfreq from the package seewave.

Examples

#First create empty folder
dir.create(file.path(getwd(),"temp"))
setwd(file.path(getwd(),"temp"))

data(list = c("Phae.long1", "Phae.long2", "Phae.long3", "Phae.long4"))
writeWave(Phae.long1,"Phae.long1.wav")
writeWave(Phae.long2,"Phae.long2.wav")
writeWave(Phae.long3,"Phae.long3.wav")
writeWave(Phae.long4,"Phae.long4.wav")
data(manualoc.df)

a <- specan(X = manualoc.df, bp = c(0, 22))

# using a diferent threshold
a <- specan(X = manualoc.df, bp = c(0, 22), threshold = 20)
# View(a)

# remove example directory
unlink(getwd(), recursive = TRUE)