Hi, I was wondering if someone could help me?
Apologies I don't know much about audio restoration.
I have been digitalising my VHS home video collection.
A couple of the videos have quite poor audio quality. Specifically a kind of echo noise on voices, especially louder voices. Attached is a sample.
I have been playing around in soundforge and audacity to try and improve but no success.
I don't know what this type of issue is called or what filters I could use to improve?
I'm not expecting much improvement, just to maybe reduce that harsh echo sound.
Thanks in advance.
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I don't hear anything like an "echo" in this sample?
Mostly it sounds like one woman is much closer to the microphone than the other people, perhaps too close in that her voice overloaded the recording level by a small amount which results in some distortion. I have no idea how you would filter that distortion, but others here my have good suggestions.
A possible related issue might apply if this is a VHS HiFi tape. Does the VCR give you an indication light on the front panel or an on-screen display of the word "HiFi"? If so, this distortion was very common: the HiFi system could provide close to CD level audio quality, but was often easy to overload when recording live events. Sometimes if you're lucky, manually switching the VCR from auto-detection of HiFi audio to force playback of the backup non-HiFi Normal/Linear audio track instead will get rid of this specific distortion. But it may not help, or if it does you'll trade eliminating the distortion for overall lower quality, more muddy sound. Of course, if this is not a HiFi tape, the distortion is present in the Normal/Linear track and there won't be an alternative HiFi track to compare with.
From this limited sample, I wouldn't say the distortion is constant or terribly intrusive: overall this sounds like a typical family camcorder video from the tape-based camcorder era. Perhaps younger ears with no context or experience of that era would consider this utterly atrocious, but it really is fairly common.
It certainly is not an echo, but you do have distortion from an amplifier being over-driven. If you don't hear this when you watch the tapes, then the problem is in your capture setup, and perhaps you can reduce the gain in the capture chain.
If, on the other hand, you hear it when just watching the tape, then it is baked into the tape itself.
Distortion resulting from "clipping" can be removed pretty effectively by a "declipping" plugin. I believe Soundforge has one, although the one in iZotope RX is much better.
If, however, the distortion results from intermodulation distortion, there isn't much you can do about that. There are some modules in iZotope ("deconstruct") that may be able to get rid of the most annoying aspects of the screechiness in some of the laughs coming from the person in the foreground.
One problem both of them have is that an over-driven amplifier distorts the waveform in other ways beyond simply clipping the peaks (it depends a lot on the design of the amplifier: Class A, B, C, etc.). This additional distortion cannot be removed with something as simply as putting domes back on the clipped waveform, and therefore restoration is much more difficult. As I said in my last post, you then have to do what you can to reduce the annoyance caused the the distortion, usually with some sort of adaptive low-pass filtering that kicks in when the artifact is the worst.
Yes, I've used both, but obviously much more heavily Sound Forge (having used it since the 90s).
A main caveat of SF is that there's often multiple ways to accomplish what's needed. It's an extremely power application, with multiple ways to augment and restore audio.
What I mostly hear in that sample is muffle, and a distortion of spoken words due to mic volume and proximity at record time. No echo.
Something like this can be restored quite well, but it's tedious.