But maybe the device isn't meant to be a HUM on people. Maybe that is just a waste by product of it in some capacity. Change the radio frequency and you change a mood Different people respond to different things that is probably why it is layered in some concept, like music is layered.
Oh I forget what Gwen's new name is. They put her another a different name. On Aug 12, 2:01 am, Trev <[email protected]> wrote: > It could be, I have seen this before, and it could be used in an > inverse stereo or target mode BUT the transmissions would still be > obvious unless using something exotic like satellite directed lasers > and local transponders &/or implants of some kind, which would also > then be physically aparrent. > Such a device would hardly be wasted on humming at people -and also > risk questions being asked at the minimum! > It would also be resisted by shielding / not being line of sight, or > target being underground. > This effect would explain sensitivity to carrier switched microwave > systems like Tetra but this is mood affecting outcome, as a by product > [and worrying too!], but not something that would be heard, ocurring > <20 Hz in UK.. > Not sure about GWEN in the states though. > I'm looking into getting old data from a defunct site- but suspect > this will be another 'side effect' issue rather than anything malign- > but certainly worth a look.. > > On Aug 12, 7:12 am, dboots <[email protected]> wrote: > > > > >http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=P... > > > United States Patent 6,470,214 > > O'Loughlin , et al. October 22, 2002 > > > -------------------------------------------------------------------------------- > > Method and device for implementing the radio frequency hearing effect > > > Abstract > > A modulation process with a fully suppressed carrier and input > > preprocessor filtering to produce an encoded output; for amplitude > > modulation (AM) and audio speech preprocessor filtering, intelligible > > subjective sound is produced when the encoded signal is demodulated > > using the RF Hearing Effect. Suitable forms of carrier suppressed > > modulation include single sideband (SSB) and carrier suppressed > > amplitude modulation (CSAM), with both sidebands present. > > > -------------------------------------------------------------------------------- > > Inventors: O'Loughlin; James P. (Placitas, NM), Loree; Diana L. > > (Albuquerque, NM) > > Assignee: The United States of America as represented by the Secretary > > of the Air ( > > (Washington, DC) > > > Appl. No.: 08/766,687 > > Filed: December 13, 1996 > > > -------------------------------------------------------------------------------- > > > Current U.S. Class: 607/56 ; 128/898 > > Current International Class: A61N 1/08 (20060101); H04B 007/00 () > > Field of Search: 607/55,56 600/559,23,586 128/897,898 > > > -------------------------------------------------------------------------------- > > > References Cited [Referenced By] > > > -------------------------------------------------------------------------------- > > > U.S. Patent Documents > > > 3563246 February 1971 Puharick > > 3629521 December 1971 Puharick > > 4835791 May 1989 Daoud > > > Primary Examiner: Schaetzle; Kennedy > > Attorney, Agent or Firm: Skorich; James M. Callahan; Kenneth E. > > > STATEMENT OF GOVERNMENT INTEREST > > > The invention described herein may be manufactured and used by or for > > the Government for governmental purposes without the payment of any > > royalty thereon. > > > BACKGROUND OF THE INVENTION > > > This invention relates to the modulating of signals on carriers, which > > are transmitted and the signals intelligibly recovered, and more > > particularly, to the modulation of speech on a carrier and the > > intelligible recover of the speech by means of the Radio Frequency > > Hearing Effect. > > > The Radio Frequency ("RF") Hearing Effect was first noticed during > > World War II as a subjective "click" produced by a pulsed radar signal > > when the transmitted power is above a "threshold" level. Below the > > threshold level, the click cannot be heard. > > > The discovery of the Radio Frequency Hearing Effect suggested that a > > pulsed RF carrier could be encoded with an amplitude modulated ("AM") > > envelope. In one approach to pulsed carrier modulation, it was assumed > > that the "click" of the pulsed carrier was similar to a data sample > > and could be used to synthesize both simple and complex tones such as > > speech. Although pulsed carrier modulation can induce a subjective > > sensation for simple tones, it severely distorts the complex waveforms > > of speech, as has been confirmed experimentally. > > > The presence of this kind of distortion has prevented the click > > process for the encoding of intelligible speech. An example is > > provided by AM sampled data modulation. > > > Upon demodulation the perceived speech signal has some of the envelope > > characteristics of an audio signal. Consequently a message can be > > recognized as speech when a listener is preadvised that speech has > > been sent. However, if the listener does not know the content of the > > message, the audio signal is unintelligible. > > > The attempt to use the click process to encode speech has been based > > on the assumption that if simple tones can be encoded, speech can be > > encoded as well, but this is not so. > > > A simple tone can contain several distortions and still be perceived > > as a tone whereas the same degree of distortion applied to speech > > renders it unintelligible. > > > SUMMARY OF THE INVENTION > > > In accomplishing the foregoing and related object the invention uses > > a. modulation process with a fully suppressed carrier and pre- > > processor filtering of the input to produce an encoded output. Where > > amplitude modulation (AM) is employed and the pre-processor filtering > > is of audio speech input, intelligible subjective sound is produced > > when the encoded signal is demodulated by means of the RF Hearing > > Effect. Suitable forms of carrier suppressed modulation include single > > sideband (SSB) and carrier suppressed amplitude modulation (CSAM), > > with both sidebands present. > > > The invention further provides for analysis of the RF hearing > > phenomena based on an RF to acoustic transducer model. Analysis of the > > model suggests a new modulation process which permits the RF Hearing > > Effect to be used following the transmission of encoded speech. > > > In accordance with one aspect of the invention the preprocessing of an > > input speech signal takes place with a filter that de-emphasizes the > > high frequency content of the input speech signal. The de-emphasis can > > provide a signal reduction of about 40 dB (decibels) per decade. > > Further processing of the speech signal then takes place by adding a > > bias level and taking a root of the predistorted waveform. The > > resultant signal is used to modulated an RF carrier in the AM fully > > suppressed carrier mode, with single or double sidebands. > > > The modulated RF signal is demodulated by an RF to acoustic > > demodulator that produces an intelligible acoustic replication of the > > original input speech. > > > The RF Hearing Effect is explained and analyzed as a thermal to > > acoustic demodulating process. Energy absorption in a medium, such as > > the head, causes mechanical expansion and contraction, and thus an > > acoustic signal. > > > When the expansion and contraction take place in the head of an > > animal, the acoustic signal is passed by conduction to the inner ear > > where it is further processed as if it were an acoustic signal from > > the outer ear. > > > The RF to Acoustic Demodulator thus has characteristics which permit > > the conversion of the RF energy input to an acoustic output. > > > Accordingly, it is an object of the invention to provide a novel > > technique for the intelligible encoding of signals. A related object > > is to provide for the intelligible encoding of speech. > > > Another object of the invention is to make use of the Radio Frequency > > ("RF") Hearing Effect in the intelligible demodulation of encoded > > signals, including speech. > > > Still another object of the invention is to suitably encode a pulsed > > RF carrier with an amplitude modulated ("AM") envelope such that the > > modulation will be intelligibly demodulated by means of the RF Hearing > > Effect. A related object is to permit a message to be identified and > > understood as speech when a listener does not know beforehand that the > > message is speech. > > > Other aspects of the invention will become apparent after considering > > several illustrative embodiments, taken in conjunction with the > > drawings. > > > What is claimed is: > > > 1. A method of encoding an input audio signal a(t) to produce a double > > sideband output signal having a .omega..sub.c carrier frequency, which > > when transmitted to the head of a receiving subject, will by the radio > > frequency hearing effect induce a thermal-acoustic signal in the bone/ > > tissue material of the head that replicates the input audio signal and > > is conducted by the bone/tissue structure of the head to the inner ear > > where it is demodulated by the normal processes of the cochlea and > > converted to nerve signals which are sent to the brain, thereby > > enabling intelligible speech to be perceived by the brain as any other > > nerve signal from the cochlea, the method comprising: applying an > > input audio signal a(t) to an audio pre-distortion filter with an As > > (f) filter function to produce a first output signal a(t)As(f); adding > > a very low frequency bias A to the first output signal to produce a > > second output signal a(t)As(f)+A; applying the second output signal to > > a square root processor to produce a third output signal (a(t)As(f) > > +A).sup.1/2 ; applying the third output signal to a balanced modulator > > to produce a double sideband output signal (a(t)As(f)+A).sup.1/2 sin > > (.omega..sub.c t), where .omega..sub.c is the carrier frequency; and > > transmitting the double sideband output signal to the head of the > > receiving subject. > > > 2. The method of claim 1, wherein the As(f) filter function step > > further comprises the step of de-emphasizing the high frequency > > content. > > > 3. The method of claim 1, wherein the further step of suppressing one > > of the sidebands of the double sideband output > > ... > > read more »- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Hum Sufferers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hum-sufferers?hl=en -~----------~----~----~----~------~----~------~--~---
