Short version: They use a technique that others do as well : Dr Haben and Dr Remarcle was mentioned here in the forum, Prof Nawka in Berlin and someone in Stuttgard do a similar thing as well, apparently someone in the UK also does the same basic technique. BUT there are differences in how they do it - I would not recommend the two german clinics, they seem to be less good, use not enough care. Prof Remarcle uses some extra caution, using glue in addition to threads to stabilize the suture and he orders a longer voice rest for healing than the german doctors. Dr Kim at Yeson clinic uses permanent thread and avoids lasers but rather works with microscalpels. So each one has small differences and I think they reflect in the success rate of the surgery. In Berlin it apparently is only a 30% happiness rate, at Yeson it is 70-80%.
The tecnique is shortening of the vocal folds by a glottoplasty - basically suturing hte vocal folds together at the front to make them shorter.
At Yeson clinic, costs are about $8000, at Prof Remarcle its about 2/3 of that I believe.
(plus travel and hotel). the surgery is short, 60-90 minutes and one can go home to the hotel the same day at Yeson, some surgeons will keep you for 1-2 nights.
Followup at Yeson is a week after surgery and then you can fly home.