OpenAI has unveiled its most advanced speech-to-speech model, gpt-realtime, and the Realtime API, enhancing customer support automation with new features like SIP telephony. Peter Bakkum, a technical staff member, stated that this simplifies the creation of voice-over-phone solutions. The entry of gpt-realtime into the market poses a significant challenge to many voice AI startups. Notably, T-Mobile has begun testing these advancements, claiming substantial initial improvements in customer interactions.