.modulationSpectrum: Modulation spectrum per sound

Description

Internal soundgen function.

Usage

.modulationSpectrum(
  audio,
  amRes = 5,
  maxDur = 5,
  logSpec = FALSE,
  windowLength = 15,
  step = NULL,
  overlap = 80,
  wn = "hanning",
  zp = 0,
  power = 1,
  normalize = TRUE,
  roughRange = c(30, 150),
  amRange = c(10, 200),
  returnMS = TRUE,
  returnComplex = FALSE,
  plot = TRUE,
  savePlots = NULL,
  logWarpX = NULL,
  logWarpY = NULL,
  quantiles = c(0.5, 0.8, 0.9),
  kernelSize = 5,
  kernelSD = 0.5,
  colorTheme = c("bw", "seewave", "heat.colors", "...")[1],
  col = NULL,
  main = NULL,
  xlab = "Hz",
  ylab = "1/KHz",
  xlim = NULL,
  ylim = NULL,
  width = 900,
  height = 500,
  units = "px",
  res = NA,
  ...
)

Arguments

audio: a list returned by readAudio
amRes: target resolution of amplitude modulation, Hz. If NULL, the entire sound is analyzed at once, resulting in a single roughness value (unless it is longer than maxDur, in which case it is analyzed in chunks maxDur s long). If amRes is set, roughness is calculated for windows ~1000/amRes ms long (but at least 3 STFT frames). amRes also affects the amount of smoothing when calculating amMsFreq and amMsPurity
maxDur: sounds longer than maxDur s are split into fragments, and the modulation spectra of all fragments are averaged
logSpec: if TRUE, the spectrogram is log-transformed prior to taking 2D FFT
windowLength: length of FFT window, ms
step: you can override overlap by specifying FFT step, ms (NB: because digital audio is sampled at discrete time intervals of 1/samplingRate, the actual step and thus the time stamps of STFT frames may be slightly different, eg 24.98866 instead of 25.0 ms)
overlap: overlap between successive FFT frames, %
wn: window type accepted by ftwindow, currently gaussian, hanning, hamming, bartlett, rectangular, blackman, flattop
zp: window length after zero padding, points
power: raise modulation spectrum to this power (eg power = 2 for ^2, or "power spectrum")
normalize: if TRUE, the modulation spectrum of each analyzed fragment maxDur in duration is separately normalized to have max = 1
roughRange: the range of temporal modulation frequencies that constitute the "roughness" zone, Hz
amRange: the range of temporal modulation frequencies that we are interested in as "amplitude modulation" (AM), Hz
returnMS: if FALSE, only roughness is returned (much faster)
returnComplex: if TRUE, returns a complex modulation spectrum (without normalization and warping)
plot: if TRUE, plots the modulation spectrum of each sound
savePlots: if a valid path is specified, a plot is saved in this folder (defaults to NA)
logWarpX, logWarpY: numeric vector of length 2: c(sigma, base) of pseudolog-warping the modulation spectrum, as in function pseudo_log_trans() from the "scales" package
quantiles: labeled contour values, % (e.g., "50" marks regions that contain 50% of the sum total of the entire modulation spectrum)
kernelSize: the size of Gaussian kernel used for smoothing (1 = no smoothing)
kernelSD: the SD of Gaussian kernel used for smoothing, relative to its size
colorTheme: black and white ('bw'), as in seewave package ('seewave'), or any palette from palette such as 'heat.colors', 'cm.colors', etc
col: actual colors, eg rev(rainbow(100)) - see ?hcl.colors for colors in base R (overrides colorTheme)
xlab, ylab, main, xlim, ylim: graphical parameters
width, height, units, res: parameters passed to png if the plot is saved
...: other graphical parameters passed on to filled.contour.mod and contour (see spectrogram)