osc: Oscillogram

In soundgen: Sound Synthesis and Acoustic Analysis

Oscillogram

Description

Plots the oscillogram (waveform) of a sound on a linear or logarithmic scale (in dB). To get a dB scale, centers and normalizes the sound, then takes a logarithm of the positive part and a flipped negative part, which is analogous to "Waveform (dB)" view in Audacity. For more plotting options, check the "oscillo" function in the seewave package.

Usage

osc(
  x,
  samplingRate = NULL,
  scale = NULL,
  from = NULL,
  to = NULL,
  dynamicRange = 80,
  dB = FALSE,
  returnWave = FALSE,
  reportEvery = NULL,
  cores = 1,
  plot = TRUE,
  savePlots = FALSE,
  embed = FALSE,
  main = NULL,
  xlab = NULL,
  ylab = NULL,
  ylim = NULL,
  bty = "n",
  midline = TRUE,
  maxPoints = 10000,
  width = 900,
  height = 500,
  units = "px",
  res = NA,
  ...
)

Arguments

x	path to a folder, one or more wav or mp3 files c('file1.wav', 'file2.mp3'), Wave object, numeric vector, or a list of Wave objects or numeric vectors
samplingRate	sampling rate of x (only needed if x is a numeric vector)
scale	maximum possible amplitude of input, used to normalize the input vector (only needed if x is a numeric vector)
from, to	if NULL (default), analyzes the whole sound, otherwise from...to (s)
dynamicRange	regions under -dynamicRange dB are treated as silent
dB	if TRUE, plots on a dB instead of linear scale
returnWave	if TRUE, returns a log-transformed waveform as a numeric vector
reportEvery	when processing multiple inputs, report estimated time left every reportEvery iterations (NULL = default, NA = don't report); see reportTime
cores	number of cores for parallel processing
plot	if TRUE, produces a plot of the results
savePlots	if TRUE, creates a subdirectory in the input directory (if input is a file or folder) or in the working directory (if input is a vector etc), named after the function (eg "spectrogram/"). All plots and audio files (if any) are saved in this new directory. If there are multiple inputs, an html notebook is also created for easy viewing and listening
embed	if TRUE and savePlots is set and there are multiple inputs, all saved images and audio (if any) are embedded in the exported html notebook for easy sharing; if FALSE, the html file links to separate images and audio files (but separate files are still saved). NB: for this to work, package "base64enc" must be installed
main	plot title
xlab, ylab	axis labels
ylim	override default amplitude scale for non-centered sounds
bty	box type (see ?par)
midline	if TRUE, draws a line at 0 dB
maxPoints	the maximum number of points to plot (speeds up the plotting of long audio files, but beware of aliasing artifacts)
width, height, units, res	graphical parameters for saving plots passed to png
...	Other graphical parameters passed on to plot()

Value

If returnWave = TRUE, returns the waveform as a numeric vector on the original or dB scale; otherwise, does not return anything.

Examples

sound = sin(1:2000/10) * approx(c(1, .01, .5), n = 2000)$y

# Oscillogram on a linear scale without bells and whistles, just base R
plot(sound, type = 'l')

# Oscillogram options with soundgen
osc(sound)             # linear
osc(sound, dB = TRUE)  # dB

# For numeric vectors, indicate samplingRate and scale (max amplitude)
osc(sound, samplingRate = 1000, scale = 100, dB = TRUE)

# Embellish and customize the plot
o = osc(sound, samplingRate = 1000, dB = TRUE, midline = FALSE,
        main = 'My waveform', col = 'blue', returnWave = TRUE)
abline(h = -80, col = 'orange', lty = 3)
o[1:10]  # the waveform in dB

# Wave object
data(speechEx, package = 'soundgen')
osc(speechEx, from = 2, to = 2.5, dB = TRUE)

# for long files, reduce the resolution to plot quickly (careful: if the
# resolution is too low, antialiasing may cause artifacts)
osc(speechEx, dB = TRUE, maxPoints = 2500)

## Not run: 
# saves oscillograms of all audio files in a folder
osc('~/Downloads/temp', savePlots = TRUE)

## End(Not run)

soundgen documentation built on Sept. 20, 2026, 5:07 p.m.