Cthulhu: The Cosmic Abyss Guide | How Does Sonar Work

How sonar frequencies work, when to scan, and how to stop missing important items.

Game Guide by Faviyan Mustafiz on Apr 24, 2026

The mechanic that makes Cthulhu: The Cosmic Abyss feel different from other puzzle games is sonar. It is not just a pulse that detects. It is a way of seeing the world through groups that normal vision can't tell apart.

It's easy to get this wrong at first and start pulsing every room in the hope that the answer will show up. That usually takes up time. The faster way is to think of sonar as a tool for targeted investigation that only works after you know what you're looking for.

Cthulhu: The Cosmic Abyss, PC, Gameplay, How Does Sonar Work, Screenshot, NoobFeed

Before scanning, make sure you unlock the right frequency

The best sonar habit is to look at clues first. The scan stops being general and starts being useful when Key takes a frequency from an object. That's why sonar and clue analysis always go together.

If a puzzle leads you to a mineral, a battery, or an organic trace, don't just look for a generic highlight to solve the room for you. Instead, look for that exact family. Being accurate is rewarded in the game. Once you get the hang of that loop, a lot of the early puzzles are a lot easier than they seem at first.

Cthulhu: The Cosmic Abyss, PC, Gameplay, How Does Sonar Work, Screenshot, NoobFeed

Don't just look at the glow; read the result

A scan that works shows you more than just an object. It gives you an idea of how the space works. If a lot of things light up at once, it usually means you still need to look at the shapes, the context, or the placement before you pick the right one.

If you only see one signal, the game is probably trying to get you to the next clean step. This is why scanning slowly is better than scanning quickly. Stop and ask yourself why that item is important. The answer is often in the puzzle itself.

Use sonar to find routes, not just things

Sonar is important for both navigation and finding things later on. It helps you figure out spaces that don't follow normal visual rules and makes rooms that would otherwise feel hostile or unreadable more organized. Sonar becomes a way to make things certain when the world gets stranger.

That doesn't mean that scanning should be used to solve every route. It means that a scan can narrow down the options, show the hidden layer in a hallway, or confirm which path really belongs to the frequency you are following.

Cthulhu: The Cosmic Abyss, PC, Gameplay, How Does Sonar Work, Screenshot, NoobFeed

This is even more important in tense parts, because panic makes everything seem important at once. Sonar gets through that noise. Don't ask what's glowing if you're stuck. Find out what the current deduction is asking you to do. That little change keeps you from going into the wrong room with the wrong frequency set.

Think of sonar as part of your build

The system also gets better as you do. As the game goes on, you get better at analyzing, scanning, and figuring out what's going on around you. That makes sonar seem less like a tutorial tool and more like the main part of your whole investigation. It matters for a good run. Strong sonar habits save time and resources, whether you're looking for a hidden item, trying to safely cross a warped area, or going after an achievement like Open Sesame or Macro Waves.

Cthulhu: The Cosmic Abyss, PC, Gameplay, How Does Sonar Work, Screenshot, NoobFeed

The short version is easy. First, look at it. Scan again. Put the result in context. If you do that all the time, sonar goes from being a confusing menu to one of the best mechanics in the game.

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