Thank you for the detailed guidance, it was very helpful. I have submitted a code-level support request asking for the PTT test app you mentioned. I appreciate your time and support!

Thank you for the detailed reply. I've submitted a bug report as requested: FB19421676 – Push-to-Talk Framework: Microphone activation tone does not play when sending while audio session is active in full duplex mode. Thanks to the context you provided regarding how the PTT framework functions, I was able to identify the cause of the transmission delay I was experiencing. It turns out that isVoiceProcessingInputMuted was set to true when starting a transmission, and only reverted to false once audio output stopped. This was the source of the delay between initiating transmission and receiving valid microphone input. By manually setting isVoiceProcessingInputMuted to false on the input node at the start of transmission, I was able to eliminate this delay and begin receiving microphone samples immediately. I'm still relatively new to Swift and iOS audio development, and I was wondering if there are any sample projects or best practices that demonstrate integrating audio with the Push-to-Talk framework. Having a reference implementation would help me avoid common pitfalls and improve how I manage audio routing and session state. Thanks again for your help!