The size of the initial circle and of the amount of decrease will vary based on the headphones. Compare with the headphone as you go. They should have a really snug fit to keep them from coming off.
Use one color...or several, depending on what you like!
Chain 2
Round 1: 6 sc in 2nd ch from hook. Sl st in first sc.
Round 2: ch 1, 2 sc in ea sc around. Sl st in first sc.
Round 3: ch 1, (sc in next sc, 2 sc in next sc) around. Sl st in first sc.
Round 4: ch 1, sc in each sc around. Sl st in first sc.
Round 5: ch 1, (sc in each of next 2 sc, 2 sc in next sc) around. Sl st in first sc.
Round 6: ch 1, sc in each sc around. Sl st in first sc.
Round 7: ch 1, (sc in each of next 3 sc, 2 sc in next sc) around. Sl st in first sc.
Round 8: ch 1, sc in each sc around. Sl st in first sc.
Round 9: ch 1, sc next 2 sts tog around. Sl st in first sc.
Round 10: ch 1, sc around. Sl st in the first sc.
Round 11: ch 1, sc next 2 sts tog around. Sl st in first sc.
Finish off.