Not being heard here means that they will not be there. This can be stated in active form. Alternate translation: "Harpists, musicians, flute players, and trumpeters will no longer make a sound in your city" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-metonymy]])
Not being found there means that they will not be there. Alternate translation: "No craftsman ... will be in your city" (See: [[rc://en/ta/man/translate/figs-metonymy]])
The sound of something not being heard means that no one will make that sound. Alternate translation: "No one will use a mill in your city anymore" (See: [[rc://en/ta/man/translate/figs-metonymy]])