dot-audSpectrogram: Auditory spectrogram per sound

In soundgen: Sound Synthesis and Acoustic Analysis

Auditory spectrogram per sound

Description

Internal soundgen function.

Usage

.audSpectrogram(
  audio,
  step = 1,
  dynamicRange = 80,
  filterType = c("butterworth", "chebyshev", "gammatone")[1],
  nFilters = 128,
  nFilters_oct = NULL,
  filterOrder = if (filterType == "gammatone") 4 else 3,
  bandwidth = NULL,
  bandwidthMult = 1,
  minFreq = 20,
  maxFreq = audio$samplingRate/2/(1 + (1/nFilters)),
  minBandwidth = 10,
  output = c("audSpec", "audSpec_processed", "filterbank", "filterbank_env", "roughness"),
  plot = TRUE,
  plotFilters = FALSE,
  osc = c("none", "linear", "dB")[2],
  heights = c(3, 1),
  ylim = NULL,
  yScale = "bark",
  contrast = 0.2,
  brightness = 0,
  maxPoints = c(1e+05, 5e+05),
  padWithSilence = TRUE,
  colorTheme = c("bw", "seewave", "heat.colors", "...")[1],
  col = NULL,
  extraContour = NULL,
  xlab = NULL,
  ylab = NULL,
  xaxp = NULL,
  mar = c(5.1, 4.1, 4.1, 2),
  main = NULL,
  grid = NULL,
  width = 900,
  height = 500,
  units = "px",
  res = NA,
  ...
)

Arguments

audio	a list returned by readAudio
step	step, ms (determines time resolution of the plot, but not of the returned envelopes per channel). step = NULL means no downsampling at all (ncol of output = length of input audio)
dynamicRange	dynamic range, dB. All values more than one dynamicRange under maximum are treated as zero
filterType	"butterworth" = Butterworth filter butter, "chebyshev" = Chebyshev filter butter, "gammatone" = gammatone
nFilters	the number of filters between minFreq and maxFreq (determines frequency resolution, while yScale determines the location of center frequencies)
nFilters_oct	an alternative way to specify frequency resolution: the number of filters per octave
filterOrder	filter order (defaults to 4 for gammatones, 3 otherwise)
bandwidth	filter bandwidth, octaves. If NULL, defaults to ERB bandwidths as in gammatone
bandwidthMult	a scaling factor for all bandwidths (1 = no effect)
minFreq, maxFreq	the range of frequencies to analyze. If the spectrogram looks empty, try increasing minFreq - the lowest filters are prone to returning very large values
minBandwidth	minimum filter bandwidth, Hz (otherwise filters may become too narrow when nFilters is high; has no effect if filterType = 'gammatone')
output	a list of measures to return. Defaults to everything, but this takes a lot of RAM, so shorten to what's needed if analyzing many files at once
plot	should a spectrogram be plotted? TRUE / FALSE
plotFilters	if TRUE, plots the filters as central frequencies ± bandwidth/2
osc	"none" = no oscillogram; "linear" = on the original scale; "dB" = in decibels
heights	a vector of length two specifying the relative height of the spectrogram and the oscillogram (including time axes labels)
ylim	frequency range to plot, kHz (defaults to 0 to Nyquist frequency). NB: still in kHz, even if yScale = bark, mel, or ERB
yScale	determines the location of center frequencies of the filters
contrast	controls the sharpness or contrast of the image: <0 = decrease contrast, 0 = no change, >0 increase contrast. Recommended range approximately (-1, 1). The spectrogram is raised to the power of exp(3 * contrast)
brightness	makes the image lighter or darker: <0 = darker, 0 = no change, >0 = lighter, range (-1, 1). The color palette is preserved, so "brightness" works by capping an increasing proportion of image at the lightest or darkest color. To lighten or darken the palette, just change the colors instead
maxPoints	the maximum number of "pixels" in the oscillogram (if any) and spectrogram; good for quickly plotting long audio files; defaults to c(1e5, 5e5); does not affect reassigned spectrograms
padWithSilence	if TRUE, pads the sound with just enough silence to resolve the edges properly (only the original region is plotted, so the apparent duration doesn't change)
colorTheme	black and white ('bw'), as in seewave package ('seewave'), matlab-type palette ('matlab'), 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)
extraContour	a vector of arbitrary length scaled in Hz (regardless of yScale, but nonlinear yScale also warps the contour) that will be plotted over the spectrogram (eg pitch contour); can also be a list with extra graphical parameters such as lwd, col, etc. (see examples)
xlab, ylab, main, mar, xaxp	graphical parameters for plotting
grid	if numeric, adds n = grid dotted lines per kHz
width, height, units, res	graphical parameters for saving plots passed to png
...	other graphical parameters

soundgen documentation built on Dec. 1, 2025, 9:08 a.m.