I have a friend who has a own echolocator.

The procedure was simple. He was instructed to count backwards from 1000 in the operation theatre. After 989 the doctors managed to implant the echolocator. The doctors were overjoyed that the procedure was a success. My friend was overjoyed that he echolocated. My friend never said anything about this. The doctors never understood what was wrong. The patient just echolocated once. It was 3 AM when I said 2 echolocate.