Google adds Brief, Critique, and Debate audio formats to NotebookLM

Google has expanded the audio capabilities of NotebookLM, its AI research and note-taking assistant, by adding three new Audio Overview formats that let users choose how their documents are presented and discussed. The company announced the additions in a post on X, saying the Brief, Critique, and Debate formats join the existing Deep Dive option and are being rolled out to users now.

Deep Dive remains the default, offering a conversational, two-host exploration of a topic. The new Brief format is described in most coverage as a bite-sized summary of the core ideas intended to last about one to two minutes, though one report mistakenly characterized it as longer. Critique delivers an expert-style review with constructive feedback aimed at helping users improve their material. Debate stages a structured exchange between two AI hosts to illuminate competing perspectives in the source material. Google said users can switch formats and adjust language, length, and prompt-based customization by tapping the pencil icon in the Audio Overview card, and that the update includes new AI voices tailored to the formats.

The update follows recent features that broaden NotebookLM’s multimedia...