Periodic Click on Audio after Cassette Transfer

Did you use Audacity’s 2.1.0 Noise Reduction? I hear some leftover bird-song artifacts in the pause. You may want to vary the settings a bit, raising sensitivity a little until you don’t get that effect. Try some increased Frequency Smoothing too, from 3 to 6, which should leave that inhalation sounding more natural.

Do what Gale says to get rid of thumps, but for amusement I saw whether my Declicker could be decent for this unintended purpose. They are not gone but much less evident with settings:

sensitivity 3,
step size 5,
max length 5,
low frequency 37.5,

otherwise as defaults. Maybe better could be found with experimentation.

https://forum.audacityteam.org/t/updated-de-clicker-and-new-de-esser-for-speech/34283/1