Improving audio quality of a wav file


I’m new to Audacity

I’m using v2.1.0 on XP

I have an MP4 file video and audio that runs for around 45 mins, unfortunately after 7mins 10 seconds the audio quality is degraded and I want to try and fix that.

I have extracted the audio into a WAV file.

Loading the WAV file into Audacity I can see that after 7mins 10 seconds the graphic changes see here

You can see in Audacity that the profile of the WAV file changes at this point, the inner column (lighter shade) becomes narrower.

The questions that I’m hoping to get some assistance with are:

  1. Looking at the audio profile (not sure if that is the right term), what ‘effect’ do I need to apply to the WAV file after 7 mins to make the inner-line the same width as the first 7 mins?
  2. When I select-all in Audacity, I am able to apply effects to the WAV file. However when I select the last 40 mins, all the effect options are grayed out, why is that?



The link says:

Error (429)
This account’s links are generating too much traffic and have been temporarily disabled!

Why is that?
It may not be possible to fix this in post-production. Where possible it is usually better to fix the cause of the problem rather than trying to repair the damage later.

I presume that you are aware of the risks in using Windows XP (Important information for Windows XP users.)


Don’t know what Dropbox is going on about, please try below link

I can’t fix the source, the source is from Youtube it is a recording of a presentation, and if I can’t fix it I have to accept it the way that it is.

But the first 7 minutes audio is excellent, so I’m hopeful (admittedly as a newbie) that I can use that “profile” as a guide to fix the rest of the file - assuming that this is actually possible.

Not concerned about XP, if you’re reassured by the fact that MS releases updates for W7 etc. I’m happy for you - but if you believe that those updates makes those versions secure you’re dreaming.

BTW the forum for me is extremely slow while browsing to other sites is normal. So I don’t see the performance issue being at my end.

Are there known issues with forum / hosting at the moment?

If you have an issue, I suggest you post here Maintaining / Improving this Forum - Audacity Forum and include the times when access was difficult and your IP Address.


Windows 7 and later Windows are demonstrably more secure than Windows XP, so please don’t mislead our users.

Of course this assumes safe usage, so avoiding torrent sites and the “dark web”.