NVIDIA Nemotron 3.5 Transcribe 30B-A4B is an open-weight speech and audio model designed for multilingual transcription, translation, speaker diarization, and audio understanding. It contains approximately 34B total parameters with 4.3B active, combining a hybrid Mamba-2–Transformer Mixture-of-Experts language backbone with dedicated speech recognition and speaker encoders. The model supports 40 languages, recordings up to one hour, and a 65,536-token context window. Its capabilities include verbatim and formatted transcription, speaker attribution, word-level timestamps, language identification, code-switching, and audio question answering. ...