AssemblyAI has introduced two new Speech-to-Text tiers, Best and Nano, offering different levels of power, capabilities, and price points. The Best tier is the default for customers and provides highly accurate transcriptions suitable for complex audio files with noisy backgrounds, multiple speakers, or accented speech. The Nano tier offers high-quality Speech-to-Text at an accessible price point, ideal for content generation, topic detection, and testing out models in a low-cost way. Users can easily switch between tiers based on their specific needs and budget constraints.