https://www.ototech.es/wp-content/uploads/2017/06/Journal-of-Hearing-Science_Vol.7-No-2.-May-2017-Abstract-Ototech-p.138-1.pdf
O.127 is about Cochlear Transmastoid Electrostimulation with a 65% of improvement in a group of more than 1000 patients. However I don't know the grade of improvement...
