Users of the ChatGPT app can now select GPT-5.6 Sol and GPT-6 Astra to power their voice interactions. Access to the GPT-6 Astra model is limited to ChatGPT Pro accounts, and the voice interface triggers the chosen model specifically when the system needs to perform a search or reasoning task.

OpenAI redesigned the voice intelligence framework to let users pick the specific model and effort level for their conversations. This shift from a fixed model to a user-selectable system integrates OpenAI's newest frontier models to improve the processing of complex queries during real-time audio chats.