From the WSJ review:
A study of 22 patients suffering from chronic pain found a 10-minute session with the Becalm Balls that included soothing music and a lavender aroma, reduced self-reported pain to 3.5 from 5.4 on a scale of zero to 10. The pain reduction was about equivalent to a control group that got a 10-minute massage by health-care workers with the music and aromatherapy. But the device has the advantage of being simple to use at home, says study co-author Carolyn S. Townsend, assistant professor at Indiana University Kokomo School of Nursing in Kokomo, Ind. The company didn’t fund the study but gave Dr. Townsend a discount on the product.