The "laughing girl" in KBC is actually a sound effect used during the show. It's not a real person, but a pre-recorded audio clip played during certain moments, usually when something funny or unexpected happens.
This sound effect is a popular part of the KBC experience, adding to the show's entertainment value and creating a lighthearted atmosphere.
While the identity of the person behind the laugh is not publicly known, it's a fun and memorable element of the show.
