You can try changing the first line of code in that section to something likeL
adsTest = audioDatastore(myfolder);
where myfolder is the folder containing your clean test signal. The rest of the section should work.
This network was trained on washine machine noise only, so I do not expect it to perform well on other types of noise. The example section uses "WashingMachine-16-8-mono-200secs.mp3" as a source of noise, but if you have another noise file, just replace the name with yours.