Fig. 1

A bone conduction voice amplifier used in this case. This device was authorized as a medical device (authorization number is 21300BZY00587000). The part that the black arrow shows was applied to the back of the patient’s ear
A bone conduction voice amplifier used in this case. This device was authorized as a medical device (authorization number is 21300BZY00587000). The part that the black arrow shows was applied to the back of the patient’s ear