Hao tong is a common Mandarin expression for pain, literally meaning so painful, and it appears in everyday speech, dramas and online videos whenever someone is hurt. As a short sound clip it circulates mainly as a reaction sound, shared in meme edits and short-form videos where a quick vocal wince is more effective than a longer explanation. Its appeal comes from its brevity and clarity: even listeners who do not speak Chinese can recognise the tone of pain at once. That universal, instantly readable reaction keeps it useful for fails, pranks and slapstick moments.