An audio microscope for analysis and annotation rather than editing
Sonic Visualiser is a program for looking at what is inside an audio file. It was developed at the Centre for Digital Music at Queen Mary University of London and is published under the GNU General Public License version 2 or later. Where a waveform editor shows you amplitude and lets you cut, Sonic Visualiser shows you frequency content over time and gives you instruments to measure it: spectrograms, pitch tracks, onset detection, beat tracking and key estimation, laid out as independent layers that share one timeline.
Reading audio in layers
A file is loaded and displayed as a pane, and layers are stacked on it. A waveform layer shows amplitude; a spectrogram shows frequency against time with a colour scale, and variants such as the melodic range spectrogram zoom in on the range where melodies live. Analysis layers come from Vamp plugins, a plugin format designed for audio analysis, and a collection of them is installed with the program. Each layer has its own parameters, so you can tune a pitch tracker to a voice or a violin rather than accepting one default for everything. Playback is synchronised with the display, and the cursor position can be read as a time, a sample number or a frame.
Annotation and measurement
The other half of the program is annotation. You can draw points, lines, regions and text on the timeline, and those annotations live in layers that can be edited, hidden and exported. That makes Sonic Visualiser useful for marking structural sections of a piece, labelling instrument entries, comparing two performances of the same work or building a reference dataset for research. Measurements can be read from the cursor and from selection ranges, and data from annotations can be exported for use elsewhere, alongside images of the display for papers and reports.
Practical configuration and limits
The Windows build is a 64-bit MSI installer, and versions exist for macOS and Linux. The program is an analysis tool rather than an editor: it does not destructively process your audio, and it does not replace a digital audio workstation. Very long recordings and several simultaneous spectrogram layers consume a lot of memory, particularly at high frequency resolution, so working at a lower resolution and zooming in is usually wiser than opening everything at once. Plugin installation is a manual step, and the quality of an analysis result depends on choosing a plugin suited to the material rather than on the program itself.
Who should choose something else
Audacity or Ocenaudio is the better tool when the task is to cut, clean up or process audio, because Sonic Visualiser will not change the sound. If you only need a quick look at the frequency content of a file, a lightweight spectrogram viewer is faster to open. And for phonetic research with detailed labelling conventions, Praat remains the domain-specific standard, while Sonic Visualiser is the more general instrument for music and signal analysis.
- Best for
- Students, researchers and engineers who need to measure audio rather than edit it: pitch and tempo analysis, spectrogram inspection and annotation of recordings.
- Good to know
- Analysis layers come from Vamp plugins, and results are only as good as the plugin you choose. It is not an audio editor, so nothing here changes the sound of the file.
Sonic Visualiser shows you the contents of a recording and lets you mark it up.
How to get started
- Install the 64-bit MSI from the official site and launch the program.
- Open an audio file with File and Open, then add a spectrogram layer from the Layer menu to see frequency content.
- Play the file and add analysis layers such as pitch or onset detection, tuning each plugin's parameters to the material.
Use the selection tool to measure time and frequency ranges, and save your session so the layers and annotations can be reopened later.
Questions & answers
Does it edit audio files?
No. It analyses, measures and annotates. Use Audacity or a similar editor when audio has to be cut or processed.
What are Vamp plugins?
They are a plugin format for audio analysis. Sonic Visualiser ships with a set of them, and they supply features such as pitch tracking and beat detection.
Can I export my annotations?
Yes. Annotation layers can be exported as text or CSV data, and the display itself can be saved as an image for reports.
