KJV:

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.
45 And he said unto me, This chamber, whose prospect is toward the south, is for the priests, the keepers of the charge of the house.
46 And the chamber whose prospect is toward the north is for the priests, the keepers of the charge of the altar: these are the sons of Zadok among the sons of Levi, which come near to the LORD to minister unto him.

NASB:

44 From the outside to the inner gate were chambers for the singers in the inner court, one of which was at the side of the north gate, with its front toward the south, and one at the side of the south gate facing toward the north.
45 He said to me, "This is the chamber which faces toward the south, intended for the priests who keep charge of the temple;
46 but the chamber which faces toward the north is for the priests who keep charge of the altar. These are the sons of Zadok, who from the sons of Levi come near to the LORD to minister to Him."

‫מד  וּמִחוּצָה לַשַּׁעַר הַפְּנִימִי לִשְׁכוֹת שָׁרִים, בֶּחָצֵר הַפְּנִימִי אֲשֶׁר אֶל-כֶּתֶף שַׁעַר הַצָּפוֹן, וּפְנֵיהֶם, דֶּרֶךְ הַדָּרוֹם; אֶחָד, אֶל-כֶּתֶף שַׁעַר הַקָּדִים, פְּנֵי, דֶּרֶךְ הַצָּפֹן.

‫מה  וַיְדַבֵּר, אֵלָי: זֹה הַלִּשְׁכָּה, אֲשֶׁר פָּנֶיהָ דֶּרֶךְ הַדָּרוֹם, לַכֹּהֲנִים, שֹׁמְרֵי מִשְׁמֶרֶת הַבָּיִת.

‫מו  וְהַלִּשְׁכָּה, אֲשֶׁר פָּנֶיהָ דֶּרֶךְ הַצָּפוֹן, לַכֹּהֲנִים, שֹׁמְרֵי מִשְׁמֶרֶת הַמִּזְבֵּחַ: הֵמָּה בְנֵי-צָדוֹק, הַקְּרֵבִים מִבְּנֵי-לֵוִי אֶל-יְהוָה--לְשָׁרְתוֹ.

For singers there are balconies from the side of the Temple. Similar balconies on the side of the outer courtyard can be used for the blowing of the shofar. On the first and second floors of these buildings are locker rooms for the Kohanim, with 18 cabins on each floor. If the priestly service is organized in two shifts, morning and evening, then these two buildings will allow 18 Kohanim to serve in the Temple and 18 Kohanim to serve at the altar  in each shift. (see also Ezekiel 42:13,14)