This can be stated in active form. Alternate translation: "The noblemen hushed their voices" or "The noblemen stopped speaking" (See: [[rc://en/ta/man/translate/figs-activepassive]])
This represents them having so much respect for Job that they had nothing to say. Alternate translation: "they felt that they were unable to speak" or "they had nothing to say" (See: [[rc://en/ta/man/translate/figs-metonymy]])