Though most know Google's AI-powered research assistant, NotebookLM, for its viral features like Audio Overviews and Mind Maps, these features weren’t part of the original launch when the tool first debuted under Google Labs. In case you don't know what Google Labs is, it's essentially Google's experimental playground where the tech giant rolls out early versions of its AI tools to gather feedback and refine them before releasing them more widely. What's interesting is that not all of Google Labs' experimental projects make it past the testing phase. Some get shelved completely.

NotebookLM's one of the projects that made it through, and Google’s been constantly updating the tool with unique features and improvements. Though Audio Overviews is definitely one of the main reasons I’m addicted to the tool, the feature isn’t without its flaws. Thankfully, while testing out different Google Labs experiments to see how they stack up against NotebookLM, I came across an experiment Google’s working on that fixes nearly every gripe I've had with Audio Overviews.

Google Labs Illuminate project is centered around Audio Overviews

Think NotebookLM, without the extras

Illuminate is a Google Labs experiment that's meant to "foster learning." It’s designed to transform content into short, AI-generated audio discussions. If you're thinking, "hold up, isn't that exactly what NotebookLM does?" — same, I don't blame you. That’s exactly what ran through my mind when I first read about Illuminate.

The difference is that Illuminate is built with Audio Overviews as the primary focus and is meant to primarily convert research papers into audio discussions.

Whereas in NotebookLM, you can convert any content you upload (PDFs, lecture slides, YouTube videos, and more) into Audio Overviews. Keep in mind that while Illuminate is centered around the idea of converting research papers into audio discussions, it does let you convert any web content (unless it’s paywalled, the site has opted out of indexing, or the content has been flagged by Illuminate's safety filters). Unlike NotebookLM though, you can't generate podcasts from documents, YouTube videos, PDFs, Google Docs, and more.

Though this did feel like a limitation at first, it also means that Illuminate's Audio Overviews feature is much more refined and focused, especially for students and researchers. It also means that if it ends up launching widely, unless Google adds more features to it (which I don't think it will), Illuminate will likely stay focused on just Audio Overviews.

If Google keeps the spotlight on this one feature, there's a good chance it'll continue refining and improving it in ways that just aren’t possible within a more feature-packed tool like NotebookLM.

As I mentioned, Illuminate isn't available widely just yet. You’ll need to sign up for a waitlist through Google Labs to try it out. I've noticed the waitlist notification only seems to appear if you're outside the U.S. I was able to access it using Opera’s built-in VPN. In case you still can't access it and are stuck on the waitlist, the good thing is you’ll still have the option to listen to a few research paper conversations curated by Google.

Illuminate's Audio Overviews come with a transcription

A treat for the can’t-listen-without-captions gang

One of the biggest complaints I've had with NotebookLM's Audio Overviews is that they don't have transcriptions. I can't watch a TV show, movie, or even a TikTok without subtitles or closed captions nowadays! Naturally, I found it super frustrating that I couldn’t read along or refer back to anything while listening to NotebookLM's summaries. Without a transcript, there's no easy way to search, skim, or even quote anything from it. Having to guess where to scrub back just to replay a specific point is annoying, especially when you're dealing with longer overviews.

Thankfully, Illuminate's Audio Overviews don't have this issue. Any audio discussion you're listening to comes with a full transcription, with the host and guest clearly labeled throughout. Clicking on a specific line in the transcript instantly jumps you to that exact moment in the audio, making it super easy to revisit key points or double-check something you missed. It’s a small touch, but it makes a massive difference in how usable and accessible the feature feels.

Illuminate has publicly available Audio Overviews

When you’re in the mood to explore, not generate

Sometimes, you're in the mood to learn something new but don’t necessarily have your own research paper or document to upload. Illuminate is divided into two parts: Explore and Generate. The Generate tab lets you, well, generate an Audio Overview. What I really find interesting, though, is the Explore page, which lets you listen to conversations (i.e., Audio Overviews) from "groundbreaking research papers" and "the most classic books."

For instance, some of the research papers I found included The Illusion of Artificial Inclusion, Code as Policies: Language Model Programs for Embodied Control, Learning to Reason with LLMs, and The Nobel Prize in Chemistry 2024. On the other hand, some of the classic books include Alice's Adventures in Wonderland, Pride and Prejudice, and The Adventures of Sherlock Holmes. A play icon, along with the duration of the Audio Overview, is displayed right below each title. Upon clicking it, you'll hear a two-person AI-generated conversation between a virtual AI host and a guest.

NotebookLM, on the other hand, is only limited to the content you personally upload. There’s no public library to explore if you just want to casually learn or sample something new. Though that is something I personally love, since NotebookLM's meant to help you engage with information you already have better, that doesn't mean I don’t appreciate Illuminate's Explore option. Even if you don’t have anything to generate an overview from, you can still pop in, hit play, and learn something interesting on the go.

Your generated Audio Overviews are saved in one place

No more regenerating from scratch

Another massive complaint I've had with NotebookLM's Audio Overviews from day one is the fact that you can't save one you've generated for a certain notebook within it. Every time you open a notebook again, you need to regenerate the Audio Overview from scratch. Since I primarily use NotebookLM for studying, I revisit my notebooks often, and needing to generate an overview every single time is just tedious.

The only workaround is to download the Audio Overview to my device, which kind of defeats the purpose. All the Audio Overviews you generate in Illuminate are saved in a My Library section. They’re all drafts, though, and expire 30 days after creation, but it's still better than having nothing saved at all. You also have the option to download the ones you'd like to keep for longer, which is always an added bonus.

Try out Illuminate today

If you love NotebookLM's Audio Overview feature as much as I do, you need to try out Illuminate right away. I genuinely hope it's eventually released widely, and can't wait to see how it evolves.