Hello all. I need help with an audio file. I’m no audio engineer but I really need someone to give me a hand. I can barely hear parts of this audio file. How should I begin? Can I post a copy of the audio file here (mp3) so you can preview?
Before you post, give us a head start. Windows? Which One? Laptop? Which version of Audacity exactly?
Describe the show. Rock Concert? Trying to record a phone call? Guitar strumming?
Koz
Thanks for the quick reply! It was a phone call I recorded on my laptop. The original call was on my iphone. Unfortunately, Audacity crashed when I first tried to save the file but I managed to recover most of the audio. I’m using 1.2.6. The problem is that the other user’s voice is very faint. I have tried using normalize and compressor but it just makes the audio worse and I can’t hear anything. I’m not sure how to fix the file and it’s a really important file.
Windows? Recording a phone call looks like it should be easy. It’s not.
So yes. Post a little of it with some of your voice and some of the caller. If you know where the built-in microphone of your laptop is, you can park the iPhone right next to it and do remarkably well.
Koz
Well, the recording has already taken place. What I’m trying to do is fix the audio now and I’m not sure how to proceed. Here is a sample of some audio: http://sharesend.com/nxech
There’s a lot missing from the other person’s reply, i.e. dropout …
A dropout is also a momentary loss of signal in a communications system, usually caused by noise, propagation anomalies, or system malfunctions. For analog signals, a dropout is frequently gradual and partial, depending on the cause. > For digital signals, dropouts are more pronounced, usually being sudden and complete, due to the cliff effect. > In mobile telephony, a dropout of more than a few seconds will result in a dropped call.
http://en.wikipedia.org/wiki/Dropout_(electronics)
Dynamic range compression can’t amplify what isn’t there …
if you have both voices on the same recording you will have to pick all of the low parts with their voice and amplify/normalise each one separately.
if you only have their voice recorded and normalise didnt help you dont have much you can do now, so get a better recording in the future.
Apart from the low volume there is also a lot of other “damage” to the recording.
There are “bubbly harmonic” sounds that are typical of “MP3 compression” and “Noise Reduction”.
I can’t tell how much of this other “damage” is directly from the iPhone, and how much has occured after.
Is the recording that you posted a direct unprocessed export of your Audacity recording, or have you already attempted to clean it up a bit?
The ideal sound sample to post would be one that is the original recording, unprocessed, and exported from Audacity in WAV or Flac format (these formats will not cause additional damage, whereas MP3 does). How close to that can you get?
Thanks Steve. That is a good point. Unfortunately, Audacity crashed at some point when I tried to save the original audio file. Immediately after my call with the other person I attempted to make edits to the original audio file to improve sound. Then I saved. I still have an original Audacity file (with I believe a few loudness edits). Those bubbly sounds are probably coming from the noise removal I may have done to the original audio.
Looks like I might not have much I can do here overall
The tools only work really well once. If you have no unprocessed original work and the only material you have is already damaged by bad application of the tools, that’s pretty much the end of the story. We can’t recover from that.
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What happened to that sound? We might be able to help with that. Do Not compress to MP3 for posting. You should be able to get five or six seconds of WAV to post here onthe forum. Compress to FLAC or ZIP to get more. Those two do not damage the sound.
Koz
I bet It’s noise reduction: the bubbly artifacts are too high pitched to be due to extreme mp3 compression which has very little high frequency content.
The bubbly artifacts are on both sides of the conversation, so those artifacts on Fullmotiongroup’s voice can’t be due to iphone.
The other person’s voice is intelligible in a few places so the problem is mainly due too dropout on the mobile phone, (e.g. poor reception)
I agree that the majority is almost certainly from the noise reduction - it certainly sounds like it.
The problem with “compression damage” is that it is cumulative. A bit of damage from the 'phone’s data compression - a bit of damage from noise removal - a bit of damage from MP3 export - put them all together and there’s a lot of damage and not much (if anything) you can do to fix it.
I’d not like to guess if/how much the drop-outs are caused by poor reception, it could just be caused by excessive noise removal.
BTW Trebor, there could be a little task that you’ll find interesting coming up (if the user posts a sound sample): https://forum.audacityteam.org/t/making-ufo-sound-in-far-distance/13804/1
OK, so I found an old project file with AU files and was able to join them together with a file joiner. This file is the closest I have to original but obviously as mentioned here have lost some data already. Given the sample attached here, are you able to provide some guidance on what settings to use in Compressor, Amplify, so forth?
I haven’t found much luck in getting combinations of compressor or other Audacity processing to work.
I’ve applied Chris’s compressor with default values except compression ratio set to 0.8 , the result can be heard here.
No compressor or other processing can amplify what isn’t there: the result of multiplying zero by anything is still zero.
If you can find the original recording (before any noise reduction had been applied) and apply Chris’s compressor you’ll get better results.
If you’re using Windows there is a free programme which can recover deleted files , (provided they have not been overwritten) …
Recuva (pronounced “recover”) is a freeware data recovery program, developed by Piriform, and runs under Microsoft Windows Vista, XP, 2003, 2000 and 98. Windows 7 support is preliminary, with more developments coming soon. It is able to recover files that have been “permanently” deleted and marked by the operating system as free space. The program can also be used to recover files deleted from flash/USB drives, memory cards or MP3 players.
Are you at all interested in telling us how you did that so we might be able to fix it before hand next time?
Koz