I am using Mac High Sierra (10.13.6). Here is another suggestion suggested by a user at http://ssrubin.com/posts/fixing-macos-bluetooth-headphone-audio-quality-issues-with-hammerspoon.html#comment-4018174387
"Hi, I found another way to "fix" this without using scripts or apps.
Open the standard "Audio MIDI Setup.app" utility, and click the + at the bottom to create an Aggregate Device. Then select the Internal Microphone as the only component in this aggregate device and select it as the default input."
I tried to follow theses steps but I am confused on the internal mic part. I go to Audio.MIDI Set up, click the little + and see a new Aggregate Device. I see only four check boxes, Built in Mic and output and my two airpods. Where is the internal mic? and what do I do after I select it?