vvolhejn
Joined 5 years ago
Joined 5 years ago
Basically, yes, sort of expected: we don't have detailed enough control to precent it fully. We can measure how much it happens and train better models, but no 100% guarantee. The bigger the model, the less this happens, but this one is tiny, so it's not the sharpest tool in the shed. Hallucinated bits can theoretically happen but I haven't observed it with this model yet.
For text, there are a few papers that train the tokenization and language model end-to-end, see: https://arxiv.org/abs/2305.07185
It's also a tiny model for LLM standards, with 150M parameters. The goal wasn't really to reach state of the art but to show how the performance of a single language model architecture can be vastly different when you just change the tokenizer.
That being said, having a more constrained model can also lead to some really cool stuff. The DDSP paper learns how to control a synthesizer to mimic instruments: https://arxiv.org/abs/2001.04643
You could probably do something similar for a speech model. The result would not sound as good but you could get away with much fewer parameters, because much of the modelling work is done by the assumptions you put in.
Compare also KokoroTTS, a tiny TTS that's so tiny because it uses a handcrafted system to turn text into phonemes, and then just synthesizes from those phonemes: https://huggingface.co/spaces/hexgrad/Kokoro-TTS
But categorical distributions are better for modelling. It's a little difficult to explain here without using diagrams. The intuition is that if you try to have a model predict the next embedding and not the next token, you can't model multimodal distributions - you'll end up predicting the mean of the possible continuations and not the mode, which is not what you want.
Check out Section 5.3 and Figure 6 from PixelRNN, where they discuss this phenomenon: https://arxiv.org/pdf/1601.06759
At the bottom of the blog, I link two articles that do make continuous embeddings work. One of them is the Kyutai paper Continuous Audio Language Models: https://arxiv.org/abs/2509.06926
The recent MiMo-audio bunches tokens into "patches" of four timesteps and has the model predict those. [2]
[1] https://arxiv.org/abs/2005.00341
[2] https://github.com/XiaomiMiMo/MiMo-Audio/blob/main/MiMo-Audi...
See Section 4.2 in the Moshi paper: https://arxiv.org/pdf/2410.00037
[1] https://mira-wm.com/blog-post/#hidden-information