He wonders if Miyagi is still alive and clears his throat, then he is asked, 'Who is there?,' which is his wife Miyagi's voice, though it sounds husky.
もしやと思って咳をすると、向うから「誰（たそ）」と声がしたのは、しわがれてはいるけれどまさしく妻、宮木のものだった。