# Textually Pretrained Speech Language Models

# NeurIPS submission 3371

## Abstract:

Speech language models (SpeechLMs) process and generate acoustic data only, without textual supervision. In this work, we propose TWIST, a method for training SpeechLMs using a warm-start from a pretrained textual language model. We show using both automatic and human evaluation that TWIST outperforms a cold-start SpeechLM across the board. We empirically analyze the effect of different model design choices such as the speech tokenizer, the pretrained textual model, and the dataset size. We find that model and dataset scale both play an important role in constructing better-performing SpeechLMs. Based on our observation, we present the largest (to the best of our knowledge) SpeechLM both in terms of number of parameters and training data. We additionally introduce two spoken versions of the StoryCloze textual benchmark to further improve model evaluation and advance future research in the field.

## Natural speech examples:

| Generated
Prompt | Cold Init.-1.3B | TWIST-1.3B | TWIST-7B

## LibriLight:

Prompt | Generated | Ground truth (resynthesized from speech tokens using a vocoder)

## LibriSpeech:

Prompt | Generated | Ground truth (resynthesized from speech tokens using a vocoder)