This is the best video on the internet. Blake's cousin and her husband had a baby girl just before Reese had the twins. Reagan was born deaf. She had a cochlear implant done in January (or, as April referred to it: implants - leading to lots of confusion for folks not as "in the know"), and this is the video of the bionic ear activation...truly one of the most wonderful things I've ever seen.
In case it's not clear, the doctor activates the bionic ear, then says "Ba-ba-ba" to see if Reggie reacts.