上课铃声才是中国好声音
[shàng kè líng shēng cái shì zhōng guó hăo shēng yīn]
Meaning 'The school bell is China's best voice', it humorously references a popular Chinese TV show called 'China's Got Talent' but replaces 'talent' with the sound of a school bell. It can suggest nostalgic sentiments about school days or imply that everyday sounds carry more value than celebrity performances.