This meme is closely connected to Among Us, the social deduction game that exploded online in 2020. The phrase “when the impostor is sus” spread across TikTok, YouTube, Discord, and remix culture as players and meme creators turned the game's “sus” slang into a standalone joke. The audio is still used because it instantly communicates suspicion in a silly, internet-native way. It often appears alongside other quick reaction sounds, including bruh, especially in short edits built around obvious or exaggerated reveals.