CoSTA Decouples Speech Token Spaces to Speed Up Spoken Dialogue Models

CASIA · hf · 2026-10-30

CoSTA, a paper from CASIA and collaborators, addresses inefficiency in spoken dialogue models (SDMs): sharing one speech-token space between generation and synthesis yields long autoregressive sequences and costly inference, while swapping in lower-rate tokenizers introduces compression–quality trade-offs and expensive replacement.

CoSTA is a compatibility-preserving post-hoc framework that decouples the generation and synthesis token spaces: an adapted SDM outputs shorter compressed speech tokens, which a deterministic expansion module losslessly restores for the original speech decoder. This preserves quality and decoder compatibility while substantially shortening the autoregressive sequence and speeding up inference.

Original post →

More from Research

Research channel →