The word "bowl" refers to what is in it. See how you translated this in [Revelation 16:2](./02.md). AT: "poured out the wine from his bowl" or "poured out God's wrath from his bowl" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This means someone sitting on the throne or someone standing near the throne spoke loudly. It is unclear who is speaking. (See: [[rc://en/ta/man/translate/figs-metonymy]])