Using the Mimi codec for metalinguistic representations

Abstract

In this paper, we focus on the dictionary of 2048 tokens used in Mimi semantic token codebook, the neural codec of the Moshi language model. We show that the ABX experiment carried out with Mimi fails to capture the mapping of the semantic tokens to phone realisations. By realigning Mimi representations to the TIMIT corpus transcriptions, we show that the 2048 tokens IDs of the semantic codebook map to quadphone, triphone, biphone, phone and subphone realisations.

11 pages, accepted for the Proceedings of the Third Workshop on the Bridges and Gaps between Formal and Computational Linguistics (BriGap-3), Paris 2026