Damaged/Distorted Audio Recording

Report · Mar 08, 2017

Hello,

I have some interview audio recordings that really need a fix. They were damaged by a faulty Tascam recorder and now I need to fix them in post.

NOTE: THESE ARE NOT CLIPPED FILES.

I tried diagnostics DeClipper but that was impertinent because they were recorded with perfect levels. The problem is not background noise, hiss, or anything like that, it is hard for me to identify. I don't have the language to describe the problem, but attempting to describe it I would say it sounds like a robotic/digitize sound effect was applied to the original file. I hear blips of high pitched "artifacts" in the file. It is almost as if the original bit rate of the file was too low.

The best way to diagnose this would be if I send the a sample file to anyone who would like to help. I just need an email address.

Thank you so much for helping me!

(P.S. I am using the latest Adobe Audition)

Report · Mar 08, 2017

It's probably best if you post a short sample of the problem to something like Dropbox or box.net so several of us can download it and have a listen.

My instinct is that a total fix is unlikely but there may be things you can do to minimise the problem at least.

Report · Mar 10, 2017

Hello Bob,

Thank you for replying to my plea for help! I have uploaded a sample to my Google drive which I believe can be downloaded by anyone with a link. Here it is:

DAMAGED_SAMPLE.mp3 - Google Drive

Report · Mar 11, 2017

The file you supplied, although nominally stereo, has audio only on the left channel. That may be deliberate but the problem of the "robotic" sound you refer to is very evident.

In my experience, this is caused by excessive use of Noise Reduction. You mention using diagnostics>declipper, but that would not create the effect you are hearing, IMO. Do you still have the original file, i.e. before you applied the declipper? If so, can you post a sample of that somewhere? Unless you do have the unaltered original, I fear those artifacts are "baked in" to your audio.

Jeff

Report · Mar 12, 2017

Sorry for not jumping straight back in...some real life medical issues got in the way!

Anyway, I have to agree with emrecs. Your robotic sound sure sounds like too much NR and if that's the case, you can only fix it by going back to the original.

However, one other thing. As emrecs says, I'm only hearing left channel audio too, If you audio started off as stereo but was converted to mono, if some kind of phase error crept into the conversion, this could also be a possible cause--though with modern software/gear this is less likely.

Report · Mar 12, 2017

Bob and emmrecs,

Firstly, I appreciate all the help I can get. You two are a God-send. I am taking everything you two have discerned into consideration.

At this point, I should let you know that the file you downloaded is the Original and not the filtered/edited version. I may be up a creek.

Perhaps some strange filter on my Tascam recorder was active during the recording? Being that as it may, can we think of other solutions than aforementioned?

Aside from re-recording, are there any filters or features in Adobe Audition that can remove the excess "robotic" sounds? How can I restore the files through editing?

Thanks again

Report · Mar 12, 2017

I can't comment on whether any "strange filter" was in use on your recorder as you worked (you need to check that yourself, perhaps) but, since you say that file you gave us is the "original", I have to say your chances of being able to perform ANY sort of edit to remove the robotic sounds is nil, sorry.

In addition to the point raised by both Bob and myself re the absence of any usable audio in the right channel, is also the matter of the very low bit rate of 32kbps. Is that really the original recording (mp3, left hand channel only AND low bit rate) or did you actually convert it for upload to Dropbox?

Hopefully, the original is a wav file! If it is, can you select a short section of it (e.g. no more than 20 seconds or so) and post that to Dropbox?

Jeff

Report · Mar 12, 2017

Yup. I also sort of assumed the 32kbps was a conversion to make the Dropbox files smaller. If that's the original quality then I fear you might be sunk. There's no way to replace what's been damaged. Other than recorders for office dictation, I've never heard of a recorder with such low quality though. If you still have the original Tascam recording available, I'd suggest you check that and hope the fault was a playback/transfer issue and doesn't reflect the original recording,

I'm afraid if that was the original then there are no magic filters you can use to fix it.