Xin tong is a common Mandarin expression for emotional pain, literally describing a heart that aches, and the two characters are widely understood across Chinese speaking communities. As a short audio clip it circulates online mainly as a reaction sound rather than as a song or film quote, because the meaning is clear even in isolation. Creators reuse it in short videos, chat stickers with sound, and edited memes where a brief cue for sadness, loss or romantic disappointment is needed without a longer performance.