Ability to play waiting sound indicator or model response of "I'll look that up", to signify processing.

[jakeatmsft]

This issue is for a: (mark with an x)

- [ ] bug report -> please search issues before submitting
- [x ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Minimal steps to reproduce

When using AI search in VoiceRAG solution while the agent is performing RAG, an audio indicator that plays while processing would help identify how to manage the session channels for handling more complex conversation scenarios.

Any log messages given by the failure

Expected/desired behavior

OS and Version?