A.T. Robertson Commentary Acts 22:2

"And when they heard that he spake unto them in the Hebrew language, they were the more quiet: and he saith," — Acts 22:2 (ASV)

He spake (προσεφωνε). Imperfect active, was speaking. See aorist active προσεφωνησεν in 21:40.

They were the more quiet (μαλλον παρεσχον ησυχιαν). Literally, The more (μαλλον) they furnished or supplied (second aorist active indicative of παρεχω) quietness (ησυχιαν, old word, in the N.T. only here and 2 Thessalonians 3:12; 1 Timothy 2:11ff.). Precisely this idiom occurs in Plutarch (Cor. 18) and the LXX (Job 34:29). Knowling notes the fondness of Luke for words of silence (σιγη, σιγαω, ησυχαζω) as in Lu 14:4; 15:26; Acts 11:18; 12:17; 15:12; 21:14,40. It is a vivid picture of the sudden hush that swept over the vast mob under the spell of the Aramaic. They would have understood Paul's Koine Greek, but they much preferred the Aramaic. It was a masterstroke.