There is a range of computer programs that can represent acoustic energy graphically in a spectrogram. I usually use Praat, which uses a black and white gradient to represent the intensity of energy at specific frequencies and time points. Here's an example:
Often I find colour easier to interpret:
Q: Can anybody suggest free software that produces online colour gradient spectrograms?
Solutions that I have considered:
- Save Praat spectrogram, load into image processing software and replace black and white with colour gradient: too complicated
- Use Audacity: Audacity can display colour spectrograms, but the resolution is nowhere as good as in Praat and no combination of options (window size and function) seems to improve that. Here's an example:
(Note that the latter spectrogram is wide-band and the first in Praat narrow-band, but changing wide-band to narrow-band doesn't solve the problem in Audacity).