Peak Finder

As a result of a recent enquiry on the developers mailing list, I had a look through some of my old plug-ins.

There is an old plug-in by Edgar-rft which is on the wiki (documentation and a minor bug fix updated today)
and here is an old one that I wrote which I have just updated (bottom of page).

This plug-in can either:

  1. Locate the highest peak in the selection.
  2. Locate peaks that are over a given threshold level (dB)

(The “stf” suffix to the name is just to distinguish it from Edgar’s plug-in.)


  1. Time accuracy: [Choice: Normal,Best (slow). Default = Normal]
  • The normal setting will create a region label around the detected peak. If only the highest peak is being detected, the region label will be 1/100th second long. If peaks above the threshold are being detected, the region labels will be 1/100th second longer than the peak.
    • “Best (slow)” usually takes much longer to process (up to 10 times slower) but is accurate to within one sample period. If only the highest peak is being detected, a point label will be created close to the highest sample value. If peaks above the threshold are being detected, region labels will be created around each peak from immediately before the first sample to exceed the threshold value, ending immediately after the final sample of the peak that exceeds the threshold value.
  1. Peaks to find: [Choice: Max peak only (default), Peaks above threshold]
  • When “Max peak only” is selected, if there is more than one peak at the maximum level, the first peak to reach the maximum level will be labeled.
    • When “Peaks above threshold” is selected, all peaks that exceed the threshold level will be labelled.
    • Note that peaks may be up or down. The plug-in does not differentiate between positive going peaks and negative going peaks."
  1. Threshold (dB): [-15 dB to 0 dB. Default = -3 dB] This control is ignored when labeling only the maximum peak.
  2. Maximum number of labels: [1 to 10000. Default 1000] Sets a limit to the maximum number of labels that may be created.

peakfinder-stf.ny (2.9 KB)


Along the same lines as this plugin, is there one that detects the HIGH and the LOW peak of an audio file? I noticed most analyzers always detect and return the highest peak. I’m also interested in capturing the lowest. Does such a plugin exist that returns both values?


What do you mean by “lowest peak”? That sounds like a contradiction.

Sorry for using the wrong terminology. I meant to call out the highest and lowest db value in an audio file. Hope that makes sense.

The is an easy little trick with the Amplify effect to find the peak. Your file has already been “secretly” and Audacity knows the peak… The Amplify effect defaults to whatever gain is needed for 0dB peaks. So for example, if Amplify defaults to +3dB your peaks are currently -3dB.

The optional [u]ACX Check[/u] plug-in will give you the “noise floor” which is the quietest 1/2 second, and it will also give you the peak.

It’s possible for the quietest part to be minus infinity dB (digital “dead silence”). You’ll find dead silence between tracks on a CD.

Awesome. Thank you :slight_smile: