Unique Application - Need Help with Nyquist Script

Hi there,

I have recordings of air pulses and I need to find a way to automatically determine the number of pulses per second. Typically they are in the range of 5-20 Hz. So far I have been able to do this manually.

Here is my manual workflow:

  1. 1kHz high pass filter (48dB rolloff)
  2. 3kHz low pass filter (48dB rolloff)
  3. Amplify until I get clipping during the pulse but not in between pulses
  4. Noise Gate to silence audio in between pulses (-100dB level reduction, gate threshold -6dB, attach/decay 10ms)
  5. Run a modified version of bpm_count.ny to calculate the air pulse frequency in [Hz]

Here is an example of what the final waveform looks like:
air pulse.png
Instead of step #5, I would like to be able to export the peaks and their corresponding time to a text file and analyze it in Excel. Something like this:
air pulse with peaks.png
Is this possible using Audacity/Nyquist? Could someone point me in the right direction?


How long are the files that you want to analyze?