Del Ferro method

The Del Ferro method to combat stuttering focuses on teaching voluntary control over the diaphragm. Proponents of the method hold that uncoordinated movements of the diaphragm are the core cause of stuttering.

The method was developed by the American opera singer Leonard Del Ferro, who settled in Amsterdam and founded the Del Ferro Institute there in 1978. The method is only taught in Amsterdam, and a command of the Dutch language is required.