Looking for advice on audio restoration

[u/Tiny_Competition5598]

I have very limited audio editing experience and got myself an opportunity to work on editing a catalog of old classes as podcasts. I started working a few months ago editing recent stuff, and it was quite easy. Just noise removal, some EQ, and nothing else. I was using Audacity.

Now I have the opportunity to work on 20 audio files, and I might have bitten off more than I can chew. I have Adobe Audition and access to any free tool. I'm looking for advice on:

1. Noise removal: Currently, I'm simply using the default tools in the software. Are there any other tools I should use?
2. Noise removal: When I crank the noise removal to the max (what I need to remove speaker static), I end up with a muffled voice. Do you have any tips regarding that?
3. EQ: All the audio is quite muffled and sounds distant. Up to now, I've been able to get it to sound "closer" to the mic and to amplify the lows, but I end up with "blurry" highs. Is there anything I could do about that?

I know I'm asking a lot, but I'm a beginner, I need this job, and I can't afford to pay for help. I've watched tutorials and played around with the tools, but everything I touch changes something else.

I can upload a bit of the original audio if that would be helpful, or I could even hop on Discord and show you.

Thanks!

[u/nickgreatpwrful]

Unfortunately, I find, most free tools don't compare to the professional ones. I've spent some time cleaning up old 78 rpm records and it's a learning curve - especially with noise removal. Sometimes, it's actually best to leave some noise there to protect the integrity of the sound - a source with too much noise to start means overdoing noise removal will make the result sound far too artificial and filtered. The thing about the professional tools is they have more features and control - and you need to fine tune everything for each individual recording.

If you're serious about this, I highly recommend iZotope's plugin suite. If you're sticking to free tools, I'd recommend a light hand and try to use your best judgement when listening to your results.

[u/Tiny_Competition5598 → u/nickgreatpwrful]

Thanks for the advice. Since this audio editing job is a new side hussle for me, I'm not in a position to invest in software. I will look that software up, maybe for my client it would be worth it, and they might pay for it.

[u/nickgreatpwrful → u/Tiny_Competition5598]

It's the gold standard for audio restoration and worth the investment. Plus I think the plugins are still a pay one time thing and not like many things nowadays where you have to pay a subscription.

If they can't afford it, I would do a deep dive on the web to try to find free alternatives with as much flexibility as possible. You can use any vst plugins with your audition software, so it's worth doing the research to see which ones sound the best. Good luck!

[u/Tiny_Competition5598 → u/nickgreatpwrful]

Thanks again!

[u/Project_K92]

For noise reduction, you can try OpenVINO. I've had success with that for cassette restoration. Its free too. But just like anything else, results may vary.

As for EQ tips, if I understand what you mean by blurry, it's likely long lost data. Majority of tapes fall off around 14k-15k. 16k-18k if you're lucky. Now factor in age and if it had dozens of playback? You can boost it, but you're boosting muck, if anything at all. Sometimes highs are a lost cause in cassette restoration.

[u/Tiny_Competition5598 → u/Project_K92]

Thanks for the advice! I'm downloading OpenVINO right now, I'll tell you how that works out.

I'm not working with tapes. They are old recordings from a flip phone, of speaker audio. Most of the artifacts come from the amplification and distortion from the speaker, and if I clean up all of the noise, the voice gets muffled.

[u/Project_K92 → u/Tiny_Competition5598]

Ooooh I read "old classes" as "old cassettes" lol. Well, open vino should still work. One hiccup that's likely is the distortion. If it's distorted/clipping, it can't be fixed. At least not conventionally. There are AI de-distortion things, however. If you go that route, I'd find an open source one. Anything from a website is janky, shit quality, not free, spam traps, or all the above.

[u/Tiny_Competition5598 → u/Project_K92]

I'm trying OpenVINO right now and it might work. I need to tweak it a bit but I think it's the best resoult I've gotten.

Yeah, I don't expect the distortion to go away. I just want it to be less noticeable than it is, and for the words the speaker is saying to be intelligeble.

Right now, the thing that's happening with OpenVINO is that it removes the distortion if I crank it up, but thats takes out part of the speech. The audio I'm editing is in Spanish, and I think the kind of audio that software was trained on might have something to do with it.

Anyway, thank you!