These are the same word translated "growl" in verse 29. Use your language's word for the sound of waves in a storm or heavy rain or some other frightening natural sound.
Here darkness represents suffering and disaster. This metaphor can be stated in active form. Alternate translation: "the dark clouds will completely block the light of the sun" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])