Acoustic Adventures

Did you hear? New Challenges are out now!

Galen Reich & Merel Zoet
April 06, 2026

Welcome all…

To a new Bellingcat Open Source Challenge Newsletter. We have five exciting new exercises ready for you —get ready to look listen for clues!

We’ll also look back at last month’s challenges, reviewing your write ups and videos. Don’t forget to tag us on social media when you share how you solved the challenges, we’re always on the lookout for new methods!

April Challenge - Acoustic Adventures

Have you heard of Bellingcat’s Volunteer Community? This group of people comes together to work on a variety of projects—from contributing to Bellingcat’s investigations to adding new tools to our Open Source Toolkit.

Four volunteers have now come together to create a new series of challenges for you. And they’re unlike any other you’ve seen so far: here, you’ll have to rely on your ears only.

Big thanks to Bonny, River_N, Noarno and Almal for contributing! Want to dive straight in? Find the new challenges here: challenge.bellingcat.com

Audio analysis is an important skill in Open Source Investigations. This investigation is a great example of how it can be put to practice. In the video footage showing the killing of Colombian journalist Abelardo Liz, you can’t see who shot him. But the audio could reveal the direction that the bullets came from. https://youtu.be/lf5uxI60juk?si=kiUb31pFdIbkepp7

Audio forensic experts have also helped us in the investigation into the killing of journalist Shireen Abu Akleh and an analysis of the attack on an aid convoy in Gaza.

As always, our Discord server is the place to find others working on the challenges. Join us in the #bellingcat-challenge channel!

March Background Check

SPOILER ALERT: From this point on, we’ll be discussing last month’s challenges. If you still plan to complete them, you may want to skip this section.

Screenshot of last month’s challenges

Here are the answers to the “Background Check” challenges:

MSC Euribia
Sloka
Nadjeziorna
246
7-Eleven

The creator of last month’s challenges is GeoPeter, a YouTuber and GeoGuessr pro who has been solving Bellingcat challenges and sharing how he did them. For this series, he also made a walkthrough that you can watch here:

We start with ‘Ship Happens’ and turn to this Substack post by Ali for the answers. He first extracted the picture’s EXIF data, the metadata did not provide any useful information. A reverse image search proved more useful, in particular looking for the camel. Google Lens led him to the Abu Dhabi Cruise Terminal. The cruise ship could be narrowed down by looking at the pattern visible in the background of the cruise terminal; the MSC Euribia has the same pattern painted on the sides of the ship.

For ‘On the Right Track’ we check out ‘The POTAS Corner’. In this detailed blogpost it is explained how they used OpenStreetMap Overpass Turbo to get to the answer. Using Overpass Turbo allows you to search for particular features that are logged on OpenStreetMap. In this case elements like the water tower and railway station. This combined with their hypothesis it would be in Scandinavia, because of the pin on GeoPeter’s coat, led them to narrow down the areas that included all these features. They confirmed the location by cross referencing with images from Google Maps.

‘The POTAS Corner’ also created a blogpost on the ‘Royal Company’ challenge. Here, their approach focused on background details first: EU-style license plates, regional folk art and architectural style. Using the symbols in the statue, they managed to identify the figure as Casimir III the Great, a Polish king.

The license plate became a lead, a Wikipedia page showed that the prefix NEL corresponds to a specific region of Poland: Ełk County. They continued their search in the city, Elk. Scanning green spaces in the city they pinpointed a likely location, which they confirmed by matching the decorated window in the background to a kebab shop.

For ‘No Room for Error’ we checked out how the members of GeoPeter’s Discord server did. One member, Kalvissss, recognised the setting as Sweden by looking at the road signs. They first tried an Overpass Turbo query, but didn’t manage to find a matching location this way. They changed their approach and figured the wallpaper in the room might be distinctive enough to find the hotel. On Booking.com they were surprised to see that the wallpaper was visible on the cover photo for a hotel on the first page of search results for hotels in Stockholm, Sweden.

In our Discord server, participants approached the ‘Cold Case’ challenge in several ways, but nearly everyone began by identifying the ice cream wrapper as Korean. Some then tried finding the type of ice cream, and searching its Korean name to find grocery stores that offer this brand. Others focused on the background. By reverse image searching, or looking on Google for colourful streets in South-Korea, you could find the same colourful tiles on a street in Seoul - as well as the closest grocery store that sells the ice cream.

Last month our researcher Peter Barth joined the livestream on Bellingcat’s YouTube channel. Find a recording of the stream here:

That’s it for this month’s Bellingcat Challenge Newsletter. We’d love to hear your feedback on the challenges. You can also join us on Discord and let us know if you have ideas for future challenges.

If someone forwarded this newsletter to you and you’d like to subscribe, you can do that here.

Elsewhere on Bellingcat

Before we go, here are some links to other exciting projects from Bellingcat:

See you next month!