Best AI Models in the USA

GPT-Realtime is OpenAI’s most advanced, production-ready speech-to-speech model, now accessible through the fully available Realtime API. It delivers remarkably natural, expressive audio with fine-grained control over tone, pace, and accent. The model can comprehend nuanced human audio, including laughter, switch languages mid-sentence, and accurately process alphanumeric details like phone numbers across multiple languages. It significantly improves reasoning and instruction-following (achieving 82.8% on the BigBench Audio benchmark and 30.5% on MultiChallenge) and boasts enhanced function calling, now more reliable, timely, and accurate (scoring 66.5% on ComplexFuncBench). The model supports asynchronous tool invocation so conversations remain fluid even during long-running calls. The Realtime API also offers innovative capabilities such as image input support, SIP phone network integration, remote MCP server connection, and reusable conversation prompts.

Our platform is developed in tandem with scientific innovations that reveal how people experience and express over 30 distinct emotions. Expressive understanding and communication is critical to the future of voice assistants, health tech, social networks, and much more. Applications of AI should be supported by collaborative, rigorous, and inclusive science. AI should be prevented from treating human emotion as a means to an end. The benefits of AI should be shared by people from diverse backgrounds. People affected by AI should have enough data to make decisions about its use. AI should be deployed only with the informed consent of the people whom it affects.

​Amazon Nova Sonic is a state-of-the-art speech-to-speech model that delivers real-time, human-like voice conversations with industry-leading price performance. It unifies speech understanding and generation into a single model, enabling developers to create natural, expressive conversational AI experiences with low latency. Nova Sonic adapts its responses based on the prosody of input speech, such as pace and timbre, resulting in more natural dialogue. It supports function calling and agentic workflows to interact with external services and APIs, including knowledge grounding with enterprise data using Retrieval-Augmented Generation (RAG). It provides robust speech understanding for American and British English across various speaking styles and acoustic conditions, with additional languages coming soon. Nova Sonic handles user interruptions gracefully without dropping conversational context and is robust to background noise.