Realtime sound spectrograph built with Python, PyAudio, NumPy and OpenCV.
Install PyAudio, NumPy and OpenCV. Most GNU/Linux distributions provide packages for the latter two.
python ./spectrograph.py
Press q to quit.
You can change some options at the start of the file.
I'm releasing this script into the public domain. Use it however you want, but I'd appreciate dropping me an email if you use it to build something cool.