Audio cassette tape hiss volume goes up between tracks recorded in Audacity

Hello once again Audacity Forum. I am a Windows 7 user and have Audacity 3.0.4. I am working on a project to stream and digitise a series of old audio cassette tapes using Audacity. The “source” equipment used to play the tapes is an “Ion Tape2PC” deck that has a USB “play” output with a physical volume knob. That is one way to adjust the input level of the signal sent down the USB cable and into Audacity, which is set up on my laptop. I am also using the Audacity app’s record level, as another way to adjust the signal volume.

I have found that when I stream a whole side of an audio cassette tape into Audacity and digitally record it there, despite not altering the signal volume via either of those two ways of doing so as described above, the volume of the analogue tape hiss in the “silence” between tracks sometimes gets louder, at least until the next track starts to play.

Is there some sort of volume “auto-adjust” at work in Audacity that is causing these issues? If so, is there a setting somewhere in Audacity that I can use to stop such auto-adjustment, and to keep the recording levels wherever they are, all the way through the streaming of a given side of an audio cassette tape?

I am grateful for any assistance/suggestions concerning this. Has anyone else had the same problem?

  • NelsJ

Make sure [u]Windows “Enhancements”[/u] are turned OFF.

Audacity doesn’t mess with the digital audio data but sometimes Windows does.

What I would do (and indeed what I did do when I digitized my LPs and tapes a while back) is

a) select the inter-track “silence”
b) use Ctrl+L to make ir real silence
c) use a short fade out of the preceding track where it meets the silence
d) uses short fade in of the following track where it meets the end of the silence

Repeat for each inter-track gap.

Tedious and time consuming yes - but worth it for the end result.

BTW have you considered using Audacity’s Noise Reduction effect to try to remove tape hiss from the whole recording?


Noise Reduction can be very effective for tape hiss, provided that you don’t overdo it. 6dB reduction will halve the noise level and should leave the audio sounding good. Attempting to remove the tape hiss entirely will probably make the audio sound horrible with bubbly metallic artefacts.

Forum elf Koz’ favoured settings for NR are 6,6,6


My favourite is 6,6,3, though if the original noise level is very low, the “Noise Reduction (dB)” setting can safely be pushed higher, so with good microphone recordings I may use 12,6,3.

I rarely change the “Sensitivity” from “6” unless I’m intentionally abusing the effect in some way.

I may change the “Frequency smoothing bands” from 3 to 6 when the noise is worse in the original audio (to reduce the metallic bubbly artefacts, at the expense of losing more of the audio that I want to retain).