Hi robin4k,
It sounds like you tried to delete or uninstall that program from your Mac, but it's still appearing, is that right? We'd love to help.
Just to clarify, did you use these exact steps to delete that program from your Mac? How to delete apps on your Mac
If you did use the steps in the above article to delete that program, can you let us know if you've restarted your Mac as well? If you haven't restarted your Mac yet, please do so using the following steps, and let us know if that changes anything: Log out, sleep, restart, or shut down your Mac
You also mentioned that your Mac has no sound because the sound seems to default to Nielsen Audio; are you able to change the sound output settings manually by using these steps? Change the sound output settings on Mac
Thanks!