Sonic Visualiser is a free application for inspecting and analyzing the contents of audio files.
Aimed mainly at musicians, Sonic Visualiser features powerful waveform and spectral visualization tools with annotations possible. However, its likely that you'll need to use some plug-ins with Sonic Visualizer and you may find that some work better than others. To be sure, check out the list of Vamp compatible plugins here.
Sonic Visualiser can use LADSPA and DSSI effects plugins and Windows users are at a slight advantage over Mac users as they can download some LADSPA plugins from the Audacity plugin page. Although its free, Sonic Visualiser is very powerfu. It can load audio files in WAV, Ogg and MP3 formats, view their waveforms in spectrograms and allows you to annotate audio data by adding time points and markers.
Unfortunately though, Sonic Visualiser cannot support VST plugins directly because Steinberg's VST license is incompatible with Sonic Visualiser's GPL license although both Mac and Windows users can get support using the Audacity VST Enabler.
Sonic Visualiser is an impressive free tool for musicians that will aid music learning and analysis of audio files.
