---
language:
- en
license: mit
library_name: transformers
datasets:
- fnlp/AnyInstruct
- fixie-ai/boolq-audio
- fixie-ai/soda-audio
- speechcolab/gigaspeech
---

# Model Card for Ultravox

Ultravox is a multimodal Speech LLM built around a pretrained [Llama3-8B-Instruct](https://huggingface.co/meta-llama/Meta-Llama-3-8B) and [Whisper-small](https://huggingface.co/openai/whisper-small) backbone.\
See https://ultravox.ai for the GitHub repo and more information.


## Model Details

### Model Description

Ultravox is a multimodal model that can consume both speech and text as input (e.g., a text system prompt and voice user message). 
The input to the model is given as a text prompt with a special `<|audio|>` pseudo-token, and the model processor will replace this magic token with embeddings derived from the input audio.
Using the merged embeddings as input, the model will then generate output text as usual. 

In a future revision of Ultravox, we plan to expand the token vocabulary to support generation of semantic and acoustic audio tokens, which can then be fed to a vocoder to produce voice output.
No preference tuning has been applied to this revision of the model.

- **Developed by:** Fixie.ai
- **License:** MIT

### Model Sources

- **Repository:** https://ultravox.ai
- **Demo:** See repo

## Uses

Voice agents, speech-to-speech translation, analysis of spoken audio


## Training Details

The model uses a pre-trained [Llama3-8B-Instruct](https://huggingface.co/meta-llama/Meta-Llama-3-8B) backbone as well as the encoder part of [Whisper-small](https://huggingface.co/openai/whisper-small).

The multi-modal projector is first trained (while keeping backbones frozen) in stage 1 and then in stage 2, Llama3 is also fine-tuned using LoRA.

### Training Data

Training dataset is a mix of ASR datasets (Gigaspeech), instruction-following and QA data (AnyInstruct and an extended version of BoolQ), and conversational data (SODA with alternative generations for last two turns).


### Training Procedure

Supervised speech to audio finetuning. For more info, see [training code in Ultravox repo](https://github.com/fixie-ai/ultravox/blob/main/ultravox/training/train.py).


#### Training Hyperparameters

- **Training regime:** BF16 mixed precision training
- **Hardward used:** 8x A100-40GB GPUs
- **LLM LoRA Rank:** 64

#### Speeds, Sizes, Times

The current version of Ultravox, when invoked with audio content, has a time-to-first-token (TTFT) of approximately 200ms, and a tokens-per-second rate of ~50-100 when using an A100-40GB GPU, all using a Llama 3 8B backbone.

Check out the audio tab on [TheFastest.ai](https://thefastest.ai/?m=audio) for daily benchmarks and a comparison with other existing models.

## Evaluation

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### Testing Data, Factors & Metrics

#### Testing Data

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[More Information Needed]

#### Factors

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#### Metrics

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### Results

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#### Summary