[LAU] Audio File to Graphic Thumbnail in Command Line?

I have a huge number (about 2400) of 0.5GB WAV files from live 24 track recordings. 10-40% of the tracks on some recording sets are not needed, an unused vocal mic stashed off stage. I have been using the RMS function in SOX by command line to help me determine which files are not useful. A low RMS level tends to indicate less usable signal. But, this doesn't always work. For instance, it can miss that great minute long harmonica solo during the hour long show. Peak levels don't help, because frequently a drummer will slam something loudly enough to falsely mark the file as useful, when it's actually not. Looking at the audio waveform with Ardour or Audacity seems foolproof. But, it's also way too much work to use a GUI application on that many files. I would like to run a script or program on the set of files and produce something like an Audacity or Ardour waveform graphic to be stored in a PNG (or similar) associated file. Does anyone know of something close to out-of-the-box ready to do this? I did find these possibly helpful links. http://www.network-theory.co.uk/docs/octave3/octave_263.html https://wiki.ubuntu.com/Waveform_Viewers-Plotting_Large_Analog_Data Thanks... -- Kevin