The inhabitants of Ramatis III were the humanoid inhabitants of a planet off the beaten Federation path, whose ruling family line was missing its gene for hearing, much like the Hanovers of Old Earth who suffered from hemophilia or the leaders of Fendaus V, who had no limbs. (TNG: "Loud As A Whisper")
Background information Edit
According to an internal reference document, listing all the aliens seen in Star Trek: The Next Generation, which was circulated around the time of the production of TNG Season 5, this species was identified as "Ramatisians". They were further given the description of "Humanoid, missing gene for hearing".