A narrator is someone who reads or calls out a storyline. To read or to call out, in Hebrew, is לִקְרוֹא (leek-ROH). Likewise, to tell a story is לְסַפֵּר (le-sah-PEHR).
A narrator or an announcer (such as on the radio) is a קַרְיָן (kahr-YAHN) for a male, and a קַרְיָנִית (kahr-yah-NEET) for a female.
By contrast, the narrator voice in a story is a מְסַפֵּר/מְסַפֶּרֶת (me-sah-PEHR (m) / me-sah-PEH-ret (f) ).