Exam Audio Cleanup

[linkazoid]

Hi,

 

We've been asked by our MFL department to clean up some exam recordings that sound truly awful.

 

We've tried using Audacity to remove the static and reverb, but the examiner has said that they're still unable to hear them.

 

Without resorting to having to ask the students to come back and rerecord, would anyone with proper sound fixing experience be able to try to work some magic?

 

Thanks,

 

Michael

[Andrew_C]

In Audition.

Record a section of just "static"; invert it; copy to a second (pair) track; loop*; use the fader on this track to subtract the "static". Not too much, or you'll loose content. I don't use Audacity much, you may be able to use the same trick.

 

 

As for reverb, I doubt you can undo it. You've effectively lost data.

 

 

*not done it for a while, I think loop is the right step here.

[linkazoid]

Here is a sample of what i'm trying to deal with, it's also in Italian. Sample.mp3.txt

 

Had to add .txt to get around the upload restrictions.

[Andrew_C]

Hmmm... Not quite the method I described as things have changed. I think your linguists are up a certain well known, smelly, creek.

 

You don't have a .wav do you? Might get better results...

 

Marginal improvement.mp3.txt

[linkazoid]

We do have the .wav but it's still hard to make it any better.

[Steve21]

How clean do you want it? Problem is it's so quiet a lot of cleaning makes it hard to hear, or as long as it's cleaner is that better?

 

Steve

[synaesthesia]

Surely altering the files in any way renders them inadmissible for examination?

[Steve21]

How's this sort of thing?

 

Sample-S1.mp3.txt

 

Can stick it on my home machine and try it if not

 

Steve

[linkazoid]

Surely altering the files in any way renders them inadmissible for examination?

 

The examiner has formally requested by letter that they are cleaned up, so that's what we'd use if anyone complained.

[linkazoid]

How's this sort of thing?

 

[ATTACH]36990[/ATTACH]

 

Can stick it on my home machine and try it if not

 

Steve

 

That's pretty much how clean I can make it. I can remove the audible hiss, but it makes the candidate sound like they're underwater.

[round2it]

this is why I do all the recordings (quick playback after each candidate resolves this issue)

[Andrew_C]

We often have 4 or 5 examiners recording at any one time. And they are almost always clueless numpties when it comes to "technology"* so we bought 5 identical quality recorders, and external mics. We set them up, with the mics pointing at the candidates, we set the levels. Taped over the pause switch, giving them the option of just leaving the thing running, and we'd divide it all up afterwards, or stopping between candidates.

 

After each day, we'd swap the SD cards so that the next day we could back up, then divide the long tracks, properly title, and burn to CD.

 

 

*Said numpties have no trouble internet booking flights/ferries/pedelos to France for their hols.

[SamanthaD]

Had a quick play in Adobe Soundbooth. In Tasks there's a pretty good noise removal tool, then apply an EQ boosting around 1K and higher, cutting from around 300 Hz. Play with the EQ to get rid of the underwater mudiness....

[linkazoid]

Thanks for all your suggestions. We cleaned it up as much as we could and have sent it off. we've not heard back yet so hopefully it was good enough.