Google's AI note-taking and research assistant, NotebookLM, now enables users to personalize the tone of their audio summaries. These AI-generated podcasts, hosted by virtual presenters, compile and discuss documents shared with NotebookLM, such as academic reading materials or legal briefings. When creating an audio summary, users can now select from several podcast formats: "In-Depth Discussion," "Quick Overview," "Critical Review," or "Debate." The "In-Depth Discussion" format features conversational exchanges between two AI hosts who explore a topic in detail and pose questions. The "Quick Overview" offers a concise summary designed to help users rapidly grasp the core ideas of the source material. The "Critical Review" format includes analysis and constructive feedback on the original content to aid improvement, while the "Debate" format presents opposing viewpoints from two AI hosts. Each format allows users to adjust the length of the AI podcast to suit their needs. In addition to customizable tones, Google has introduced a highly anticipated feature: new voice options for AI podcasts. This update comes as Google continues to expand NotebookLM's capabilities over recent months. Just weeks ago, the company launched video summaries, allowing users to convert complex multimedia content—such as handwritten notes, PDFs, and images—into easy-to-understand visual presentations. NotebookLM has also recently gained access to curated notebooks from various authors, publications, researchers, and nonprofit organizations, enabling users to explore a wide range of subjects. In May, Google officially released the standalone NotebookLM app for both Android and iOS platforms. According to Google, the new podcast formats will roll out in all languages and should be available to all users worldwide within the week.