The Intercept was able to uncover the suppression of audible discontent with Israel at last year’s Eurovision by examining various feeds sent out by the competition organizers for broadcast across the globe.

When the local host country’s national broadcaster — in last year’s case Sweden and SVT, respectively — produce Eurovision, they collect multiple audio feeds: such as one for the performers, one for the audience, and one for announcer voices. The broadcaster then does a live mix of the three audio feeds into a single stereo mix.

The stereo mix is beamed up to a satellite using a multichannel format which Eurovision has been experimenting with since 2004. The video feed is also sent on a separate channel. The system allows a streamlined approach for local broadcasters around the globe to access the feeds and put the program on their stations.

The audio feeds were compared using the time encoding that allows broadcasters to sync up the sound and picture. On the audience feed, cheers swell up from time to time, along with whistles and other noises of audience approval. These swells and other noises correspond between the audience feed and the stereo mix.

Notes of crowd disapproval, however, are present on the audience feed but completely absent from the stereo mix. At one point in the feed at the start of Israel’s performance, scattered boos well up on the audience feed, while the corresponding timestamp in the stereo mix has no audience sound. Likewise, at the start of the performance, an audience member can be heard prominently shouting “Free Palestine!” The cry is not on the stereo broadcast mix.