Audacity Forum

stevethefiddle wrote:There are "bubbly harmonic" sounds that are typical of "MP3 compression" and "Noise Reduction".

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.

stevethefiddle wrote:I can't tell how much of this other "damage" is directly from the iPhone, and how much has occured after.

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)

Trebor wrote:I bet It's noise reduction:

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): http://forum.audacityteam.org/viewtopic ... 12&t=29081

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.

file: http://www.fullmotiongroup.com/audacity/tobefixed.zip

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.

http://en.wikipedia.org/wiki/Recuva

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