One of the most impressive physical accomplishments of the Bene Gesserit; the idiomatic terminology used to refer to the manipulation of speech to achieve complete control over the receiver; the production of extraperceptual auditory stimuli capable of implanting a message in an individual's unconscious, thus creating a compulsion to obey. Although Voice is founded on physical knowledge, only the Bene Gesserit were able to exploit for practical purposes the knowledge that others possessed but did not understand.
Use of Voice allowed a Bene Gesserit adept to gain control over uninitiated victims merely by altering the tonal qualities of the voice. Simple instructions or orders were then spoken in Voice and obeyed dutifully.
Voice was most often used to compel a victim to do sometime undesirable to them, or to gleen the truth from an unwilling recipient.
The production of extraperceptual auditory stimuli involves manipulation of the laryngeal musculature in a manner that generates overtones well above the 20,000 cycles per second (cps) limit for conscious reception. Bene Gesserit training enables adepts to control the thyro-arytenoid, vocalis and cricothyroid muscles so as to intentionally regulate vocal quality in a manner that generated specific frequencies within the 25,000-35,000 cps range. Normal phonation, caused by tension of the vocal folds to effect condensations and rarefactions of the airstream, operates within a range of 500 to 4,000 cps, with random and only partially controlled overtones up to 10,000 cps.
It is the combinations of overtones—along with the resonating characteristics of the pharyngeal, nasal and oral cavities that amplify specific frequencies —that account in large measure for the vocal quality that makes each individual's voice somewhat unique. For instance, the trained singing voice owes its richness to overtones of more than ordinary amplitude. Skillful manipulation of Voice requires generating these overtones without altering the basic pitch or loudness of the perceived voice. Each individual word or phoneme requires a unique combination of perceived tones and extraperceptual frequencies. This perceptual/extraperceptual ratio (specific combination of perceptual and extraperceptual frequencies) must vary according to the position of a phoneme within a word, be it initial, medial or terminal.
During prehistoric times, humanity's ancestors possessed more acute hearing, sharing with numerous lesser creatures the ability to perceive high-frequency sounds. Although disuse had left them with no conscious ability to recognize or interpret such stimuli, rendering them extraperceptual, genetic memory had locked that knowledge in the unconscious. Thus, segments of the auditory cortex were merely unused, as opposed to being uncommitted. The information stored in those committed but unused zones was unavailable to the conscious mind.
Extraperceptual stimuli trigger so-called uncommitted zones of the auditory cortex. That effect frequently has been measured in the laboratory using high-frequency sounds from whistles and animals. It also is recognized that numerous languages from Old Terra, Arrakis, and Richese relied extensively on tone to denote shades of meaning. In those languages, however, tone was a digital aspect of language that required knowledge of the message code to be understood. Voice, on the other hand, registers on the receiver and creates a compulsion to obey without any previous training or conditioning of the target. That aspect of Voice requires that we engage in extensive speculation in an effort to deduce its function.
Scholars conclude that extraperceptual auditory stimuli do impinge on the nervous system by exciting portions of the auditory cortex which feeds information only to the individual's unconscious. Voice messages, therefore, go directly to the unconscious, are not subject to scrutiny by the conscious will of the receiver and compliance requires no voluntary decision.
Bene Gesserit adepts were able to monitor and control all neural and physical functions of their bodies, permitting them to hear as well as generate such stimuli. These extrasensual stimuli would also be accompanied by certain tonal qualities in audible speech. Voice messages, therefore, that went directly to the unconscious, were not subject to scrutiny by the conscious will of the receiver and compliance required no voluntary decision. However, because Voice also carried specific tonal quialities geared to the listener in audible speech, a Bene Gesserit could use Voice to compel obedience from others who would consciously believe they were acting out of their own volition, while they themselves were immune to it.
The knowledge upon which the Bene Gesserit perfected Voice appears to have been drawn from two fields of traditional learning, physics and psychology. Instrumentation capable of measuring neural activity was invented sometime during the early stages of the computer era which eventually led to the Butlerian Jihad. It was at that time that our ancestors on Old Terra created numerous electronic toys of little practical value. No doubt their lack of understanding regarding physical phenomena caused the mania for measuring such events. Instruments for registering electrical variations in the central nervous system led to the discovery that sound waves outside the normal hearing range precipitated measurable neural activity. Although primitive man probably was aware that certain animals could hear sounds humans could not, and that the human vocal mechanism could produce sounds outside the human hearing range, the distinction between hearing and neural sensitivity must have perplexed the early scientists.
The pre-Butlerian explanation for hearing was based on a mechanical-electrical process that would seem to indicate that the individual would "hear" any acoustical stimulus within the range received by the physical apparatus. Although modem science has gone well beyond such crude approximations, the "we-hear-what-we-cannot-hear" paradox was not fully explained until the secret Bene Gesserit records were uncovered by current researchers. Contemporary neuroscientists involved in the Rakis project agree that the Bene Gesserit learned, probably with the help of spice, of the static barriers in the cortex (popularly called "force field boundaries") discovered less than a century ago by the legendary Sin Qadrin.
The study of psychology seems always to have been based on the theory that surface awareness is not all there is to be found in the human mind. Although only Muad'Dib and his bloodline were successful in harnessing and using the voices within, numerous pre-Scattering notions hinted at Qadrin's theorem regarding static barriers and why some humans seemingly could draw upon racial memories of which others were unaware. For instance, reincarnation postulated that a soul reappears in successive physical bodies and the experience of past lives can, upon occasion, be brought to the conscious level. The collective unconscious theory supposed that character images or personality archetypes, implanted in the unconscious mind but outside our direct view, governed the individual's behavior. Chansiam concepts may have come closer in the assertion that all behavior resulted from guidelines passed along as a part of the genetic pattern.
The body of thought developed by Qadrin and his successors in the new science clearly shows that humans possess the potential for remembering the experiences and thought processes of all who have gone before them in their bloodline. The information is stored in the now-unused zones of the cortex, held back by the static boundaries, the force fields of the mind. It no doubt was spice that first allowed the Bene Gesserit to penetrate those boundaries.