Noise reduction makes the audio out of sync

Audacity 3 Help Forum GNU/Linux
1

First of all, I am grateful to the Audacity team for all the good things you are doing. I am able to delete noise out of my commentary successfully. The sad part is, when those few tiny bits gets deleted and I use the audio inside kdenLive, the audio and video are out of sync. Is there any method to delete the noise and replace it with blank space in the waveform ? That way those tiny bits will be silent and the audio will be in sync with the video. Any tips will be great. Thanks.

Audacity 2.3.3
Ubuntu 20.04 with Plasma desktop
Installed Audacity through Discover store, not snap.

2

Select the part that you want to silence, then “Edit menu > Remove Special > Silence Audio (Ctrl + L)”
https://manual.audacityteam.org/man/edit_menu_remove_special.html

You may want to consider using “Noise Reduction” or “Noise Gate”.

3

Thanks. I was using Noise Reduction. Never knew about Noise Gate. I will try :slight_smile:

4

Thanks. I was using Noise Reduction. Never knew about Noise Gate. I will try

Neither of those effects should affect the timing.

Audio/video files can sometimes go out-of-sync when editing or when demultiplexing/re-multiplexing the audio & video. I believe it’s caused by a timing defect in the original file that only shows-up after editing. The more-compressed formats (MPEG-4, etc.) seem to be more prone to this but I’ve it’s happened to me with MPEG-2 also.

It might help if you convert to a less-compressed format before editing (if you can do that without loosing A/V sync) but then you are going through additional generations of re-compression. Or, there are some tools for repairing MPEG timecodes and sometimes that will help. I’m a Windows guy so I can’t recommend any software.

5

My first method was deleting the noise part manually. That caused the A/V sync issue. I tried CTRL + L it looks ok. Will try in the next production environment and check how it affects the sync.