They say Hertz is first of its kind but Moshi is another duplex audio model from earlier this year that seems to perform similarly (and it runs on a MacBook):
https://github.com/kyutai-labs/moshi
- moshi https://github.com/kyutai-labs/moshi speech-text foundation model using Mimi, a SOTA streaming neural audio codec
- Mini-Omni https://github.com/gpt-omni/mini-omni multimodal LLM based on Qwen2 offering speech input and output
- Ichigo https://github.com/homebrewltd/ichigo open research project extending a text-based LLM to have native listening ability, using an early fusion technique