Can the adaptive noise reduction filter be disabled

Special Interest Groups Recording Techniques
1

I have an old voice tape of an interview with my mother that I want to faithfully reproduce. There is a lot of background noise on the tape so when I try to copy it on my PC using Audacity software, I lose too much of the original recording to effectively capture the interview. The audacity software appears to have an adaptive filter that takes out the baseline noise during the recording cutting off some of the interview resulting in this problem. The initial start of the recording with audacity seems to capture what I need; however, the “noise” is quickly suppressed resulting in chopping up the interview. Can this adaptive filter be disabled so I can faithfully capture the original?
Audacity baseline noise suppression.pdf (132 KB)

2

Audacity does not have adaptive filter that takes out the baseline noise during the recording, but your sound card may have and if you are using the microphone input on a laptop computer then there is a very good chance that it has. You will need to go into your sound card settings to turn it off. Note that the microphone inputs of on-board sound cards are usually very poor quality and produce a lot of noise if the noise reduction is not enabled. There’s no way to really get round that problem if you are using a PC laptop, other than upgrading the sound card with a USB device.

If you are recording from a tape player you should be using a stereo line-in connector rather than a microphone input. Microphone inputs are usually noisy, they are too sensitive for a tape player and will easily distort, and often they are mono.

3

Thanks for the input. I will investigate your recommendations.

4

The red lines mean clipping: signal off the scale, input too high…
red lines mean clipping-input too high.png
Looks like severe clipping at 7 & 8.5 seconds: the sound will be horribly distorted at those points.

Try reducing the output from the tape player, and/or decrease the input slider control I’ve coloured yellow.
You may have to increase the output slider (immediately left of the yellow one) after making these adjustments to maintain volume level.