Am I held accountable if another person listens to a song I was humming or listening to, even if I did not intend that for him?

If the song contains forbidden musical instruments, then the person who promotes it is sinful, because it indicates a call to evil, as it is a guide to listening to it. The Prophet, peace and blessings be upon him, said: "Whoever calls to misguidance will have sin upon him similar to the sins of those who follow him, without diminishing any of their sins." Therefore, you must repent to Allah for listening to musical instruments, advise those who do so, and clarify the prohibition of listening to them.