Researchers have been given the go-ahead to test stem cells from cord blood with the ultimate goal of reversing hearing loss in infants and toddlers whose inner ears have been damaged. U.S. regulators have approved the Phase I study, which has a primary objective of determining the safety of the experimental stem cell therapy. The therapy involves transfusing a baby's own stem cells from umbilical cord blood, banked by parents after their child's birth. Ten children aged six weeks to 18 months old with sensorineural hearing loss will be recruited for the study by doctors at Children's Memorial Hermann Hospital in Houston.