sounds issue. I cannot hear myself when I use an HDMI output to record the meeting

[JHaro]

I am using a Mac Book pro running Catalina OS. I have connected an external recorder to my HDMI output. The issue is that when I talk I can see the signal moving up and down and my colleagues can hear me. I can also hear from my headphones connected to my recorder to my colleagues in the meeting and also when I test micro and speakers. But when I talk m voice does not go through the HDMI output.  in sound system preferences my output is set to HDMi device.  I hope I have made may self clear with the issue. 

Any comments please . I am desperate. 

Cheers

Js