THIS HAS SAVED MY VOICE!!! I had prenodules and after using a microphone, they are completely healed! This has held up for me for a long time. https://www.amazon.com/Rechargeable-Amplifier-Microphone-Waistband-Presentation/dp/B06XWV9CCQ/ref=sr_1_5?crid=3VH0LOAIMTDKN&keywords=personal+microphone&qid=1650750502&sprefix=personal+microphon%2Caps%2C293&sr=8-5 My kids call it my Britney Spears mic lol.

How did you place the microphone inside the mask?

so again, this is the mask: https://i.imgur.com/ZEzlY2z.png

i cut out the large circle on the mask body and slip the microphone between the mask cover and mask body (there's enough space)

Doesn't the fact that the cable sticks out of it worsen mask fitting?

since the microphone fits between the mask body and mask cover (rather than between my face and the mask body), it doesn't worsen mask fitting.

Lastly, did you find a solution?

i didn't find a good lavalier mic; however, i just decided to, again, get a headset mic (https://www.amazon.com/gp/product/B06XWV9CCQ) and took off the headset part (https://i.imgur.com/uDaI7i0.jpg)

it doesn't have as good a form factor as a lavalier mic, but the audio quality's much better.

if you wanna hear, this comment has samples with the lavalier mic: https://old.reddit.com/r/LocationSound/comments/iym06c/inmask_microphone_dynamic_lavalier/g93x3sa/

and here are samples with the headset mic:

https://www.sndup.net/4sw9/with-mask.wav

https://www.sndup.net/999d/nomask.wav

hope that helps