dynaSpec: dynamic spectrogram visualizations

dynaSpec creates dynamic spectrograms: spectrograms that move along with the sound, ready for presentations, teaching or sharing online, without taking screen recordings of another program. They are shown as interactive web pages (with the sound embedded, click-to-play and buttons to slow the sound down), which work in R Markdown and Quarto documents, and can also be saved as videos (mp4). It builds on seewave and tuneR.

Dynamic spectrograms are built in layers, as ‘ggplot2’ graphs: dynaspec() takes the sound, and layers are added with + (only the panels added are shown):

Layer	What it does
ds_spectrogram()	Adds a spectrogram (window length, palette, amplitude range, …)
ds_oscillogram(), ds_envelope()	Add an oscillogram or an amplitude envelope (above or below the spectrogram)
ds_spectrum()	Adds a power spectrum next to the spectrogram
ds_overview()	Adds a lower panel with the whole sound to scrolling spectrograms
ds_annotations()	Highlights parts of the sound with translucent boxes, borders and labels (e.g. from a selection table)
ds_captions()	Text at a fixed position shown during a time range, like subtitles
ds_theme(), ds_theme_dark(), …	Axis titles, fonts, colors of the figure and plot, and preset themes
ds_player()	Playback controls of web pages (speed slider, loop, volume, download, …)
ds_static(), ds_scrolling() or ds_paged()	Style of the dynamic spectrogram (see below)

The package offers three styles of dynamic spectrogram:

Style	What it looks like
Static (ds_static(), default)	A play line moves over the whole spectrogram (and oscillogram), which can be split in several rows
Scrolling (ds_scrolling())	The spectrogram scrolls from right to left past a fixed “play” line, as in the Macaulay Library
Paged (ds_paged())	A spectrogram (or several “pages”) revealed by a sliding highlight box, as in Adobe Audition’s spectral view

What it looks like

The previews below are silent animations made from videos saved with save_dynaspec() (in R, printing the objects shows interactive web pages with sound).

Static spectrogram with an oscillogram, annotation lines and the ‘mako’ theme:

st <- data.frame(start = c(0.34, 1.13, 1.75, 2.34), end = c(1.03, 1.68, 2.33, 2.55),
                 labels = c("long note", "arched notes", "trill", "end note"), y = c(4.6, 4.9, 5.4, 4))

dynaspec(scythebill, flim = c(1.5, Inf)) +
  ds_spectrogram(wl = 200, collevels = seq(-50, 0, 1)) +
  ds_oscillogram() +
  ds_annotations(st, type = "line", line.freq = "y", labels = "labels") +
  ds_theme_mako()

Scrolling spectrogram with an overview of the whole sound and the Macaulay Library look:

dynaspec(antshrike, flim = c(0.5, 5.5), tlim = c(0.1, 5)) +
  ds_spectrogram(wl = 256, collevels = seq(-50, 0, 1)) +
  ds_overview() +
  ds_theme_macaulay() +
  ds_scrolling(t.display = 2, fix.time = FALSE)

Paged spectrogram, revealed by a sliding highlight box:

dynaspec(antshrike, flim = c(0.5, 5.5), tlim = c(0.1, 5)) +
  ds_spectrogram(wl = 256, collevels = seq(-50, 0, 1)) +
  ds_paged(t.display = 2.5)

Contents: Installation · Quick start · Background · Citation

[!TIP] Vignette and articles (on the package website):

• Creating dynamic spectrograms (vignette; also vignette("dynaSpec") in R): basic usage of every layer and of the three styles, and how to save and embed them
• Themes for dynamic spectrograms: theme settings and preset themes, including looks inspired by the Xeno-canto and Macaulay Library players
• Customizing dynamic spectrograms: spectrograms, panels, styles, annotations, captions, player controls and videos

Installation

Install latest version from CRAN:

install.packages("dynaSpec")

Or install the development version from GitHub (requires remotes):

remotes::install_github("maRce10/dynaSpec")

ffmpeg

Web pages do not need any external software. However, to create videos dynaSpec uses ffmpeg, which must be installed and available in the system path:

Operating system	Command (in a terminal)
Windows	winget install --id Gyan.FFmpeg -e (or download a build from gyan.dev and add its bin folder to the PATH)
macOS	brew install ffmpeg
Debian/Ubuntu	sudo apt install ffmpeg

You can check that R finds it with:

Sys.which("ffmpeg")

If ffmpeg is installed somewhere else, point R to the executable with Sys.setenv(ffmpeg = "path/to/ffmpeg").

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Citation

Please cite dynaSpec as follows:

Araya-Salas, M. & Wilkins, M. R. (2026). dynaSpec: dynamic spectrogram visualizations in R. R package version 2.0.0.9000. https://github.com/maRce10/dynaSpec

Bugs and feature requests can be reported at https://github.com/maRce10/dynaSpec/issues.