Ezekiel 40:44

And without the inner gate were the chambers of the singers in the inner court, which was at the side of the north gate; and their prospect was toward the south: one at the side of the east gate having the prospect toward the north.

The chambers of the singers - two in number, as proved by what follows: "and their prospect (i:e., the prospect of one) was toward the south; (and) one ... toward the north." So Septuagint.