Deaf flights

In the early 1900's, shortly after the invention of the plane. People came up the the "grand" idea (and I do mean that sarcastically, to use flight as a means to cure the deaf. Needless to say, this did not work. Pilots would perform acrobatic stunts in the air, doing loops, turns, and sudden drops in altitude in hopes that the changes in air pressure would restore the passengers hearing.
I first learned about this while watching a documentary entitled Through Deaf Eyes in my ASL class. In the documentary, Robert Panara explained how his father had paid for this service. Charles Lindbergh is said to have charged $50 for Deaf Flights.
I researched this on my own and found little information about it. Other than knowing it happened, I couldn't find how widespread this practice was. I did find another article that told about Hawaiian  pilot, Charles Stoffer, taking deaf man Charles N. Marques on a flight where he plunged 7,000 feet hoping to cure him of his deafness.
Below is a picture of Robert Panara from Through Deaf Eyes.

http://www-tc.pbs.org/weta/throughdeafeyes/about/transcript.pdf

http://hawaii.gov/hawaiiaviation/hawaii-aviation-pioneers/charles-stoffer