# NVIDIA Releases Real-Time Speaker Diarization Model

> The new Sortformer-based model is designed for streaming audio, identifying up to four distinct speakers in real time.

Published by The Open Weights on Oct 22, 2025. Canonical: https://theopenweights.com/news/streaming-sortformer-diarization-4spk-v2-1-3i55

## Key facts

- Company: NVIDIA
- Model: Streaming Sortformer Diarization 4spk v2.1
- Version: v2.1
- Category: Speech → Text
- Modalities: Speech → Text
- License: Other (Open weights, commercial use allowed)
- Significance: minor
- Published: 2025-10-22
- Last verified: 2026-06-17
- Hugging Face: https://huggingface.co/nvidia/diar_streaming_sortformer_4spk-v2.1
- Canonical URL: https://theopenweights.com/news/streaming-sortformer-diarization-4spk-v2-1-3i55

NVIDIA has released a new model aimed at a core challenge in audio processing: figuring out "who spoke when" in real time. The new system, [Streaming Sortformer Diarization 4spk v2.1](https://huggingface.co/nvidia/diar_streaming_sortformer_4spk-v2.1), is designed for speaker diarization on continuous audio streams, a key component for building sophisticated conversational AI.

Unlike traditional diarization systems that process an entire audio file after it has been recorded, this model's "streaming" capability allows it to work on live audio. This is essential for applications like real-time meeting transcription, automated call center analysis, and live captioning, where identifying the current speaker without delay is critical.

## Technical Details

The model uses a Transformer-based architecture called Sortformer and is optimized for common conversational scenarios. Its key features include:

*   **Speaker Capacity:** Supports up to four distinct speakers.
*   **Real-time Processing:** Designed for low-latency, continuous input.
*   **Toolkit Integration:** Intended for use with the NVIDIA NeMo toolkit for conversational AI.

The model is available for download on the Hugging Face Hub. It is released under a custom NVIDIA AI Foundation Models EULA, not a traditional open-source license, which may limit its use in some commercial applications.

## Get the model

- [Hugging Face](https://huggingface.co/nvidia/diar_streaming_sortformer_4spk-v2.1)

## Sources

- [nvidia/diar_streaming_sortformer_4spk-v2.1](https://huggingface.co/nvidia/diar_streaming_sortformer_4spk-v2.1) — Hugging Face, Oct 22, 2025

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Source: The Open Weights (https://theopenweights.com/). Aggregated and written by Claude, curated by humans. Cite as: "NVIDIA Releases Real-Time Speaker Diarization Model", The Open Weights, Oct 22, 2025, https://theopenweights.com/news/streaming-sortformer-diarization-4spk-v2-1-3i55