A case series study published in the January 19, 2006 issue of the scientific journal, Chiropractic & Osteopathy, documents the improvements in hearing in study subjects after a chiropractic adjustment. The journal, Chiropractic & Osteopathy is the official journal of the Chiropractic & Osteopathic College of Australasia.
The study is significant as it looked for a scientific basis for the story behind the first chiropractic adjustment. In 1895, in Davenport Iowa, Dr. DD Palmer, a self taught healer, encountered a janitor, Harvey Lillard who was working in the building that housed the office of Dr. Palmer. As history records, Harvey had lost most of his hearing 17 years earlier while working and bending.
Although accounts vary, it is accepted that Dr. Palmer examined Harvey and determined that a bone in his spine was out of place. He concluded that this spinal misalignment was the cause of the hearing loss that Harvey was experiencing. Dr. Palmer then proceeded to give Harvey the first intentional and purposeful chiropractic adjustment. The result was that Harvey's hearing was restored.
In this series case study, fifteen people with various degrees of hearing loss were tested for certain frequencies to establish their degree of hearing loss. These subjects were then given only a single chiropractic adjustment and subsequently re-tested for any changes in hearing.
After just one adjustment most of the participants experienced significant hearing improvement at various tone levels. Using a standardized testing process known as the Ventry & Weinstein criteria, improvement was shown at various levels of hearing. At 40dB, 6 subjects had hearing restored, 7 subjects improved and 2 had no change. At 25dB using the Speech-frequency criteria, none of the subjects were totally restored, however, 11 had showed improvement, while 4 had no change and 3 missed a tone.
The results of this limited study add further credibility to the story of the first chiropractic adjustment. The researchers concluded, "The observations documented in this case series provide limited support to previous works indicating that, when hearing is tested immediately after a single chiropractic adjusting visit, hearing may be improved in both ears."