pma-voice and proximity voice

Meridian carries radio audio itself, so it runs alongside pma-voice (or FiveM’s built-in voice) without replacing it. Players keep proximity voice as before. While they hold the radio key, nearby players also hear their side of the call through proximity voice, just as with pma-voice’s own radio.

To turn that off:

setr meridian_proximity "false"

Keep pma-voice’s own radio unused, or rebind it, so players don’t end up on two radios. Its default key is Left Alt; Meridian’s push-to-talk defaults to Caps Lock.