One of my sites states that this week the baby is the size of a turnip. About 5 inches crown to rump and weighing a grand total of 5 oz.
One another site it says that the baby is the size of an onion.
Here is a look at what's going on the inside. The umbilical cord is getting thicker to provide nutrients to the baby. The baby's bones are turning from rubbery cartilage into hardened bone and the baby can move it's joints. As for the baby's hearing that is continuing development as well.