Restoring Echoey Room Audio

Hi there,
Had a situation where I plugged my lav mic into the headphone jacks of my voice recorders (oops!) and luckily had a backup mic placed in the room. There’s a lot of echo on it, and this is something I’ve never dealt with before.

That is the recording from the backup recorder, placed maybe 4-5 feet from speakers in a small room.

Here is one of the recorders on the subjects, which was actually closer but also picked up a lot of low frequency from being on their bodies while they were talking (and not taking input from the lav mic).

I’ve played around with using them both on the same timeline and trying to compensate for the echo in the 1st mic with the nice bass from the 2nd mic, but another thing is sometimes the subjects shift in their seats, at which point the 2nd mic becomes unusable because they were basically sitting on them.

Any help with improving the room noise/echo would be much appreciated.


Oh, noise we can do (attached).

You’re stuck with the echo.

I did not have a very good sample or profile for the Noise Reduction, so I think you can do better than I did.

I’m in Audacity 2.1.2.

I selected the whole thing and Effect > Normalize: -3dB and Remove DC.
I drag-selected the pause area around 2 seconds for the profile and used the corrections: 12, 6, 6. The first number can be increased but the voice will start sounding honky. Lesser and the hiss level will come up.

The profile is required to be taken with the microphone noise only, no personal performance or body or voice sounds. That was messy. The performer gasps and fidgets and is never still.

There is no Echo Reduction tool.


The roominess can be mitigated by discarding one of the stereo tracks and making the remaining one mono, i.e. “split stereo to mono” then delete one of the (now) mono tracks.

A superior, (but slower), method is to obtain what is common to both of the stereo channels using “Vocal reduction and Isolation” tool to “Isolate centre” , that will remove some of the reverberation from the stereo recording.

Wow Trebor that’s a big improvement IMHO on the echo. I’ll try and combine the isolate centre with Koz’s noise removal and that’d be good enough for me. Thanks guys.

A tip for isolating the center:
Do it in portions of about 3 minutes.
thus, go to the selection fields, and select a length of about 3:00.25 min:sec.
Open the effect and choose the right settings, you can try a higher strength than 1.0 but not more than 2.0, it might cause artefacts.
apply the effect.
go back to the toolbar and increase the start time by 3 min (make sure that ‘length’ is checked).
Press Ctrl-r (cmd-r on Mac) to repeat the isolation effect.
Repeat the two last steps until you’re done.

The two channels are identical and you can delete one or make the track mono.
Perhaps, it will be best to do the noise reduction now, I’m not sure.