Pin the elastic to one of your outside squares. I folded it in the middle and pinned down to keep it out of the way.
Pin your other outside square on top, right sides together.
Sew around three edges with 1/4″ seams.
Turn right side out and unpin the elastic.
Repeat with the other two squares for the lining. Fold the top edge down 1/4″ to the wrong side and press.
Insert the lining into the outer bag.
Fold the edges of the outer bag in 1/4″, so they match the lining edges. Press.
Topstitch around the top of the bag.
Insert your iphone or ipod.
Wear while sewing and enjoy consistent volume of your audiobooks.