Hello,
I've found the solution of my problem. You have to allow EarMaster to you use the mic in preference system/Security and confidentiality/ confidentiality
There, allow the app to use the mic.
Best regards
Ari

Hello,
Thank you for you answer. My answer in you post.
> We can't fix a problem that we can't reproduce. We have tried to reproduce
> this on our Mac computers with 10.15, but the mic works as expected on all
> of them (Mac Mini and Macbook Pro).
the Mac is an iMac (Retina 5K, 27-inch, 2017 ...

Hello,
I add a new post under this topic because earmaster 7.1.35 on my iMac with Catalina 10.15.2 didn't detect the build in microphone.
The mic works fine when I check on other applications.
Is there a way to resolve this issue ?
Best regards
Ari