They knew the voice of the young man - They knew, by his dialect or mode of pronunciation, that he was not an Ephraimite. We have already seen ( Judges 12:6; (note)) that the Ephraimites could not pronounce certain letters.
It does not follow that they had known him before, and recognized his voice, though it may be so. But the Hebrew equally bears the sense that they heard the voice of the Levite; and, attracted by it, went into the chapel Judges 18:18 where Jonathan was. They were probably just starting on their journey, but were still within the court or precincts of Micah‘s house. Micah had evidently not told them of his house of God, and his Levite. Their questions indicate surprise.