Google has announced a major update to NotebookLM, its AI-powered note-taking and research assistant. Users can now customize the tone and format of the app’s AI-generated podcasts, called Audio Overviews.

New Podcast Formats

When creating an Audio Overview, users can choose from four distinct styles:

• Deep Dive – A conversational dialogue where two AI hosts explore a topic in detail.
• Brief – A short, focused summary to quickly capture key ideas.
• Critique – A constructive review that evaluates the sources and offers feedback.
• Debate – Two AI hosts provide contrasting perspectives on the same material.

Each format can also be adjusted in length, allowing flexibility depending on the use case.

Added Voices and Personalization

Along with customizable tones, Google has introduced new AI voices for podcasts — one of the most requested features from NotebookLM users. This enhances personalization and makes the listening experience more engaging.

Expanding NotebookLM’s Capabilities

This update follows a string of enhancements to the platform:

• Video Overviews, launched recently, convert dense notes, PDFs, and images into digestible presentations.
• Featured Notebooks from authors, researchers, and nonprofits now give users access to curated content.
• Mobile apps for Android and iOS, rolled out earlier this year, have made NotebookLM more accessible.

The new podcast formats are rolling out globally in all supported languages and should be available to all users this week.

Why It Matters

For students, professionals, and researchers, this update makes NotebookLM a more versatile productivity tool. Custom tones can help adapt AI-generated summaries for quick reviews, deeper analysis, or even critical evaluation.