welcome to the Polycom Community.
This completely depends what Platform you are using the Real Presence Desktop / Mobile to dial into.
The Application itself can mute its own microphone but what you describe is a feature of the bridge so you need to find out who is hosting this and work with them on that.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
If official support is required please check how to phone or open a case here
The title Poly Employee & Community Manager is a community setting and does not
reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer. ----------------
Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge.
Please also ensure you always check the VoIP , Video Endpoint , Microsoft Voice , PSTN or other FAQ's in the different sections