these reverse headphones do the complete opposite - YouTube
Linus Tech Tips on X: "Did you know that noise-cancelling headphones don't actually block sound? Instead, they generate sound waves that are the opposite phase as the ambient noise - essentially, inverted
How to Invert Sound on Your Headphones [Best Guide] - SoundsightR
Noise-cancelling headphones: the secret survival tool for modern life | Headphones | The Guardian
Focal Celestee – Elise Audio
Inverting the polarity on headphones dramatically changes soundstage | Headphone Reviews and Discussion - Head-Fi.org