Doven has posted some great information - I'd like to add that you may be interested in researching Sharry Edward's work on vocal profiling (founder of BioAcoustics) -
You may be surprised to learn how she got into her line of work... ;)
She has a few websites you may want to take a look at.
Also, here is an article explaining Sharry's work - Sharry Edwards
Bioacoustics Therapy Pioneer and Developer
A young woman unpretentiously stepped up to the podium and looked out at the room filled with medical professionals from all over the country. Like David standing before Goliath, she began her one hour presentation explaining the correlation she had discovered between the human voice and health. With no other credentials than a college degree in communications, she described a unifying relationship between mathematics, brainwave patterns, biochemical cascades, musical scales, vocal coherence, low frequency sound, and health. Seven hours later she was still standing at the podium answering what seemed like an inexhaustible amount of questions. The words of this modest woman resonated with such profound truth that no one in the room wanted to let her go.
The young woman was Sharry Edwards, pioneer of the emerging science of Human BioAcoustics, who has devoted her life to creating scientific research and educational programs for the advancement of energy medicine through sound. Her privately-owned educational research center, Sound Health Alternatives International, Inc., offers courses to independent research associates.
In 2001 The International Association of New Sciences awarded Sharry their top honor – Scientist of the Year to acknowledge her dedication, innovation, and leadership in the field of BioAcoustics and Sound Health.
At Temple University in Philadelphia, twelve 2002 O. Spurgeon English Humanitarian Award recipients stepped forward to receive this honor - granted to physicians and scientists who have made major humanitarian contributions to human welfare. Among the twelve were John Forbes Nash, Jr., PhD, Princeton University, Nobel Laureate (from the movie A Beautiful Mind), Norman Shealy, MD, PhD, Duke University, William Tiller, PhD, Stanford University…and Sharry Edwards, MEd, Capital University of Integrative Medicine.
Bioacoustics as a therapeutic technique originated with Sharry Edwards in 1982. Edwards found that she has a unique ability to create pure tone waveforms with her voice and hear sound frequencies outside the normal human hearing range. She was able to identify each person’s unique “Signature Sound” which seemed to be coming from their ears. Eventually she learned that these sounds are known as otoacoustic emissions, a sound which is generated from within the human inner ear. Research at the Ohio University Speech and Hearing Department in Athens clearly demonstrated that while human speech creates complex waveforms, Edwards has the unique ability to create pure tone sine waves with her voice. The spontaneous otoacoustic emissions (SOAE) Edwards hears coming from people are a function of the auditory nerve fibers in the central nervous system and sensitivity of the basilar membrane to one specific frequency. Early research of her abilities revealed that when Edwards toned a person’s Signature Sound by creating a pure tone which resonated perfectly with the otoacoustic emission she heard coming from their ears, the person’s blood pressure would drop by as much as 32 points. Edwards earliest research, published in 1982 by the University of Colorado, found that these individualized tones created an average drop in blood pressure of 8-10 points. Exploring the ear-brain-voice connection further, Edwards discovered that there is a direct correlation between stressed frequencies in the voice and the SOAE she heard.
The first bioacoustics therapy assessments were performed by Edwards listening to the sounds she heard coming from a person, and singing the sound into an audio cassette tape. The person would then listen to the recording and report any changes in their health condition. Realizing the need to create technology that would make this technique available to more than the few clients she personally was able to work with, Edwards invented a device she named a Self Management Audio Device (SMAD). The SMAD delivered low frequency analog sine waves similar to the frequencies she was able to create with her voice. Using a specially designed Korg chromatic tuner connected to computer software, early practitioners were able to identify musical notes in a person’s voice that were stressed and then test antidote sine wave formulas with the SMAD. Edwards also devised a portable tone generator to replace the original cassette tapes of her voice. Bioacoustic therapy practitioners could program these small tone boxes with the low frequency analog sine waves they identified as ones needed to support the stressed notes found in the persons voice.
Continually expanding the knowledge base and upgrading the basic process, Edwards constantly added new software programs. The Korg chromatic tuner was replaced in 1982 with the Yonda program which recorded the voice in fast Fourier transform (FFT) allowing practitioners to analyze patterns of precise frequencies along with the broader range of a musical note. Edwards also created the Bioacoustics Genesis Professional software program, organizing frequencies into harmonic patterns which reflect the mathematical matrix of muscles, biochemicals, genes, toxins, and nutrients.
The Abacus program eventually replaced the Yonda, streamlining the method of detecting stressed frequencies. Released in 2003, the Svani Vocal Profiling: From Ancient Art to Modern Math program expanded the mathematical matrix, permitting bioacoustic voice analysis to better define harmonic root cause issues. An advanced portable tone box with sophisticated features became available in 2004.
Pre-programmed tone boxes have been developed, aiding practitioners in researching the efficacy of presenting explicit frequencies in the presence of specific health conditions such as back pain, gout, and snoring.
To expedite the research of markers known to be associated with certain health conditions and their corresponding frequency equivalents, Edwards developed the Vocal Profiling Series Software which includes individual programs for nutrition, hormones, muscles, toxins, pathogens, and pre-vaccination analysis.