2.0.5 and removing mp3 artifact "glitch"

Can aynyone suggest how to remove “glitch” that is inlcluded in this song.

The mp3 artifact “glitch” is at seconds: 20-21
https://www.youtube.com/watch?v=zmomX4I9Srg

I’m attaching the slice here for inspection.

I did it by using this page from the Manual: http://manual.audacityteam.org/o/man/click_removal_using_the_spectrogram_view.html

WC

Could you elaborate what speps you did. That page refers to spectrogram view but there is no clear “spike” that you could remove easily. I’ve tried effects like “high pass” (no avail), Equalization (using Grapc-EQ to lower 1kHz-7kHz by -20 dB; it takes too much out of track). It’s hard to isolate how to approach this. The glitch is in the picture at position 0.63…0.67
Tango - Angelis - El retrato de los viejos (canta Oscar Larroca 1956) youtube zmomX4I9Srg - exerpt at 20-21s - waveform.jpg
Tango - Angelis - El retrato de los viejos (canta Oscar Larroca 1956) youtube zmomX4I9Srg - exerpt at 20-21s - spectrogram.jpg
Tango - Angelis - El retrato de los viejos (canta Oscar Larroca 1956) youtube zmomX4I9Srg - exerpt at 20-21s - equalization.jpg

  1. I downloaded your audio clip onto my desktop
  2. opened Audacity
  3. dragged your audio clip in
  4. changed the view from Waveform to spectrogram
  5. Ctrl+F to zoom to fit project in window - this is the glitch - this bit’s only easy cos I know from experience what I am looking for
  6. select around the red line/glitch I made the selection a bit wider than the red bar
  7. use Ctrl+B to label the glitch
  8. switch back to waveform view
  9. use Z to make the selection start and end on zero crossings
  10. use Edit>Delete or Ctrl+K to delete selected audio
  11. zoom in until you can see the individual samples
  12. select around the deleted section, maximum 128 samples
  13. use Effect>Repair
    15)test the result by listening closely

I suggest making a safety copy of your original audio that you can go back to if you screw up the editing or if the result is not satisfactory.

WC

Clear. I was looking for clear spike but it seems we need only to use an estimation around the area based on the spectrogram and waveform views. Thanks!

sometimes you will get very clear bright vertical bands - this one is a fairly subtle artifact

WC

Oh and thanks for the “nudge” this has given me jaalto - I’ve started work on a tutorial for various ways of fixing clicks and pops (for the Manual for the next Audacity release), something that’s been on my todo list for a fair while now :sunglasses:

WC

I found it very hard to delete enough and not hear the change in the timing.

I would say the “main” problem but not all of it is the white centered around 800 Hz and 2000 Hz. The white has the most energy and Analyze > Plot Spectrum confirms that.

I tried with the Spectral Editing tools in Audacity 2.1.0, rather than use Plot Spectrum and Notch Filter. If you draw a frequency selection with a defined lower and upper frequency, Spectral edit multi-tool performs a notch filter on that frequency selection.

I zoomed in on the vertical scale and made a selection in the affected time range from about 500 Hz to 1200 Hz centered on 800 Hz, and applied Spectral edit multi tool. Then I applied multitool to frequency selections over white areas centered on 1500 Hz and 2300 Hz, then finally selected from about 5000 Hz to 7500 Hz centered on about 6000 Hz (red areas) and applied multi tool.

That still was not quite perfect but rather than mess around any more, I found I could now delete a small enough selection that I would not notice the timing.

My hearing is no longer acute so your mileage may vary.

Gale

Same here. The length of the damage is too great to make a good repair. Just bodge it up best as you can.

I got on with this today - see http://manual.audacityteam.org/man/Tutorial_-_Click_and_pop_removal_techniques in the alpha development Manual.

WC