I need help!!!

Effects, Recipes, Interfacing with other software, etc.
Forum rules
If you require help using Audacity, please post on the forum board relevant to your operating system:
Windows
Mac OS X
GNU/Linux and Unix-like
Trebor
Posts: 9852
Joined: Sat Dec 27, 2008 5:22 pm
Operating System: Windows 8 or 8.1

Bubbly artifacts sound like Noise Reduction to me

Post by Trebor » Wed Apr 14, 2010 6:09 pm

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)

steve
Site Admin
Posts: 80752
Joined: Sat Dec 01, 2007 11:43 am
Operating System: Linux *buntu

Re: I need help!!!

Post by steve » Wed Apr 14, 2010 6:36 pm

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
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

fullmotiongroup
Posts: 5
Joined: Wed Apr 14, 2010 2:02 am
Operating System: Please select

Re: I need help!!!

Post by fullmotiongroup » Tue Apr 20, 2010 4:00 am

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

Trebor
Posts: 9852
Joined: Sat Dec 27, 2008 5:22 pm
Operating System: Windows 8 or 8.1

Post by Trebor » Tue Apr 20, 2010 5:13 am

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
Last edited by Trebor on Tue Apr 20, 2010 6:34 am, edited 2 times in total.

kozikowski
Forum Staff
Posts: 68941
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: macOS 10.13 High Sierra

Re: I need help!!!

Post by kozikowski » Tue Apr 20, 2010 5:16 am

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

Post Reply