Google's NotebookLM may introduce long 'Lecture' audio mode with new accent

Reportedly, the new Lecture mode may offer 30-minute AI audio sessions, language selection and upcoming British English narration for deeper, hands-free learning

Google is reportedly testing new ways to expand audio features on NotebookLM. According to a report by Testing Catalog, the company is experimenting with a new “Lecture” format for Audio Overviews that could generate long-form, AI-created audio sessions lasting up to 30 minutes. Alongside this, Google is also preparing to introduce new narration options, likely including a British English accent planned for a future release. While these features are not publicly available yet, the report suggests Google is working to give users more flexibility in how they listen to and review research content within NotebookLM.

What is NotebookLM Audio Overview

NotebookLM Audio Overview is an AI-powered tool that transforms uploaded documents into an engaging, podcast-style discussion. Instead of a basic text-to-speech reading, it features two AI hosts who explain and connect information from the user’s sources, making complex topics easier to understand.

 

 

NotebookLM Audio Overview update: What’s new

According to Testing Catalog, Google is now working on adding a new “Lecture” option to the Audio Overview feature. This mode appears alongside existing formats such as Deep Dive, Brief, Critique, and Debate. Unlike the current conversational style, the Lecture format is described as a comprehensive, lecture-style narration delivered by a single AI host.

 

Testing Catalog found that when the feature is used with the “Long” length option, it generates an audio lecture of about 30 minutes, with a stronger focus on detailed explanations and linking ideas across multiple sources.

 

The report also highlighted a language selector tied to the Lecture mode. As noted, users may be able to generate lectures in different languages based on their preferences. Google has already teased a new narration option for Audio and Video Overviews, likely a British English voice, which is currently mentioned as arriving in 2026.

 

According to the report, the Lecture format would likely follow the same workflow as existing Audio Overviews. Users would select their sources, choose the Lecture format, and generate the audio. Testing Catalog noted that this could be especially useful for students, researchers and professionals for exam preparation, meeting briefings or reviewing internal documents during commutes.

 

Testing Catalog also said it generated a sample lecture using available sources to demonstrate pacing and structure. However, since the feature is still hidden, Google has not shared a launch timeline, and final availability remains unclear.