Thanks for message. I would suggest splitting the audio file and deleting the noise channel out. I have outlined how to do this below.
If you would like to fix your audio file, I would recommend downloading Audacity which is an excellent free audio editor and will allow to split your audio file, delete the channel containing the noise and then return the file to stereo with two clean channels.
Once downloaded, open up Audacity. Simlpy move your cursor up to “File” and select “Import” and choose “Audio”. Find the file you want to edit and select “Open”. You will now see a box containing the wave form of the audio. In the left hand side, you will some information and “X”, the file name and an arrow pointing down. Click on the arrow and a drop down menu will appear and select “Split Stereo Track”.
Your audio track will now be split and you can delete the section will the low noise.
After you have deleting the section, move your cursor to “Edit” in the top main toolbar and from the dropdown menu select “Duplicate”. This will place an exact copy of your audio file. Go to the top audio box, click on the arrow pointing down and select “Make Stereo Track”. Your file will now be in stereo.
Finally, click on “Export” and choose a file name and WAV file format.
I have attached below two videos which you may find useful. First one is how to split a stereo track and 2nd is how to make the mono track back to stereo (no audio but shows exactly how to do it).
