Working with Special Features
Click where you want to insert your comment, then select Comment from the Insert menu.
In the Comment pane, click the Insert Sound Object button (the one with the picture of the cassette tape on it).
In the Sound Object dialog box, click the Record button (the one with the red dot on it).
Speak into your microphone. When you're finished, click the Stop button.
In the Sound Object dialog box, select Exit & Return from the File menu.
Click the Close button to exit the Comment pane.
A yellow placeholder appears where Word inserts your comment. To play your recorded comment, right-click the yellow placeholder and double-click the speaker icon in the Comment pane.