MXPA94008280A - Method and apparatus for the disturbance and the desperturbacion of audio of low co - Google Patents

Abstract

The present invention relates to audio signals woke up by modulating the double sideband of the disturbed audio signal with a modulation carrier having a carrier frequency, slightly above the highest audio signal present in the audio signal disturbed This produces a double-sideband signal that is passed through a low-pass filter, which in turn is modulated by a second carrier frequency lower than the first carrier signal equally to the perturbed signal shift spectrum original. The first bandpass filter nullifies any residual carrier of the first modulator that results from the intermodulation of the two modulation frequencies that would be audible as its output from the wake-up device. The modulators used are modulators of the low noise type which improves the signal to noise ratio in the awakened signal over the linear modulators used previously. The use of switch type modulators provides a lower cost device with improved performance. An accompanying disturbing device uses similar techniques to provide improved performance at a lower cost

Description

METHOD AND APPARATUS FOR THE DISTURBANCE AND DESPERTÜRBACION OF AUDIO OF LOW COST INVENTOR: »QN? M > QUA ». citizen of E.IJ L »with domicile in í \ Q HundßrlIcti Orive, CupartiAG, CßHfornía 95014, e.ü.A.

CAUSAHASIcNTc: m miS? Qfí CO-VORATION, a company ® E.U.A., COR domiciled in 7ÚQ et Canino Rssl East, Hounta? N Ví? W, California S4O40 »E.U.A.

EXTRACT OF THE INVENTION The audio signals were awakened by modulating the double sideband of the disturbed audio signal with a modulation carrier having a carrier frequency, slightly above the highest audio signal present in the disturbed audio signal. . This produces a double sideband signal that is passed through a low pass filter, which in turn is modulated by a second carrier frequency lower than the first carrier signal equally to the disturbance spectrum of the disturbed signal. original. The first bandpass filter nullifies any residual carrier of the first modulator that results from the intermodulation of the two modulation frequencies that would be audible "as their output from the wake-up device. The modulators used are modulators of the low noise type which improves the signal to noise ratio in the awakened signal over the linear modulators used previously. The use of switch type modulators provides a lower cost device with improved performance. An accompanying disturbing device uses similar techniques to provide improved performance at a lower cost. • k -k -k -k -k BACKGROUND This invention relates to the techniques for disturbing and alarming low-cost audio information signals. More particularly, this invention relates to a lower cost hi fi fidelity (Hi Fi) booster with improved performance over the prior art. The prior art in the technique of disturbance and audio awakening, used several techniques of frequency change. The previous techniques in audio awakening suffered from hiss in the form of "white noise", and more important in the band carrier, "hiss", caused by the intermodulation of two carrier frequencies. The above techniques also use expensive circuitry such as bandpass filters for mixing circuits, fully wideband networks of 0 degrees and 90 degrees, and circuits of 0 degrees and 90 degrees to vary carrier frequencies with constant amplitude. and the need for adjustments to the equilibrium gain of the quadrature mixers for the elimination of the sidebands. In addition, since the mixers used in the prior art are not stable over time, their deviations result in an audible whistle as a result of an escape through the carrier. The prior art requires mixers that need pure sine wave modulation, therefore a truly analog multiplier is needed. True analog multipliers tend to have noise problems due to the configuration of their circuits that cause thermal or impulse white noise components that degrade the signal to noise ratio (SNR) of the audio disturbance system. Prior systems in the art have one or more of the identified problems and include U.S. Patent Nos. 4,636,853 ('853), DYNAMIC AUDIO SCRAMBLING SYSTEM, by Forbes, issued on 13 January 1987, No, 5,058,159, METHOD AND SYSTEM FOR SCRAMBLING AND DESCRAMBLING AUDIO INFORMATION SÍGNALES (METHOD AND SYSTEM FOR THE DISTURBANCE AND DESPERTURBATION OF AUDIO INFORMATION SIGNALS), by Quan issued on October 15, 1991, and No , 5,159,631, AUDIO SCRAMBLING SYSTEM USING IN BAND CARRIER (AUDIO DISTURBANCE SYSTEM USING BAND CARRIER), by Quan et al., issued on October 27, 1992 ('159). A review of the prior art will be useful to better understand the present invention. Turning now to the drawings, Figure 1 is a block diagram of the key elements of the prior art of Forbes' 853. The Forbes' wake-up device '853 has a disturbed audio input 34 which is connected to a phase changer of all the steps 20, which contains an output of 0 degrees 38, and an output of 90 degrees 39. The disturbed audio signal has a displacement frequency 36 f-f2 as shown in Figure 2a. This shows the disturbed audio offset by a displacement frequency determined by the disturbance process. The phase change outputs are connected to a first input of linear modulators 21 and 27. A frequency generator 22 generates a square wave frequency (fx) which is fed to the band pass filter 24 to remove any harmonics, producing this way a pure sine wave. This sine wave fx is connected to a phase shifter of 0 degrees and 90 degrees 25. The outputs of the phase shifter 25 in turn are connected to second inputs of linear modulators 21 and 27, respectively. The outputs of the first and second linear modulators are added in the adder 28 to produce the signal 37. This output signal 37 is connected to a first input of a second mixer 30 by a high pass filter 29 passing only f? and the upper sideband, as shown in Figure 2b. A second square wave frequency generator 23 generates a signal f2, as shown in Figures 1 and 2b. This square wave is filtered by the bandpass filter 26 to remove any harmonics to produce a pure sine wave signal. This pure sine wave signal is connected to a second input of third mixer 30. The output of third mixer 30 is connected to a low pass filter 31 to produce an unbalanced output signal 35. The second spectral diagram in Figure 2b shows the input to the third mixer 30. The frequency f-j_ here represents the supply of the residual carrier through the mixers 21 and 27. Figure 2c shows the relationship of a carrier f2 af in Figure 2b, and the signal disturbed audio shown in Figure 2a. Figure 2d shows the relationship of the spectral characteristics of the awakened signal 35 and the residual component of the frequency difference (f1-f2) to the spectral characteristics of the signals in Figures 2a-2c. Figure 4 shows the disturbed audio input of the Quan's 11th prior art. This shows the displacement of the disturbed audio 40 by a displacement frequency determined by the original disturbance process. The disturbed audio input signal 40 is connected to an all-pass changer 41 which provides 0-degree and 90-degree phase change outputs 42 and 43 to the first inputs of the first and second mixers 44 and 45. The generator carrier frequency 46 generates a sine wave signal fc 47, with a frequency of one Khz or 2-3 Khz. The carrier frequency 47 is filtered by a low pass filter 48 to remove any harmonics to produce a pure sine wave 49. This pure sine wave signal 49 is connected to a step 50 all phase shifter to produce signals from 0 degrees and 90 degrees 51 and 52, which in turn are connected to second inputs of the mixers 44 and 45. The outputs of the mixers 44 and 45, the signals 53 and 54, are connected to the adder 55 to produce the Awakened output 56. Figure 4b shows the relation of the band alarm carrier fc to the disturbed audio signal. Figure 4c shows the awakened audio spectrum with the residual carrier fc which is typically -60 decibels below the awakened audio program, but is still audible during the silent passages of the audio program. Thus, it is an object of this invention to provide an improved operational wake-up device and / or disturbed low frequency frequency change audio signals. The described method and apparatus: (1) Eliminates the use of phase change circuits of 0 degrees and 90 degrees; (2) eliminates the use of quadrature mixing circuits; (3) eliminates the need for bandpass filters or low pass filters for the corrugation carrier; (4) reduces white noise and cost by using switch type mixer circuits instead of linear mixers; (5) eliminates the audible hiss in band by filtering the whistle of the first residual carrier; (6) eliminates the need to adjust the mixers for a minimum whistle of the in-band carrier; and (7) since the signal to noise ratio has been improved, the need for noise reduction circuits has been eliminated. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of the key elements of the prior art of Forbes. Figure 2 is a spectral diagram of the system in the prior art of Forbes. Figure 3 is a block diagram of the key elements of the prior art of Quan et al. Figure 4 is a spectral diagram of the prior art of Quan et al. Figure 5 is a block diagram of the preferred embodiment. Figure 6 is a spectral diagram of the preferred mode of the wake-up device described in Figure 5. Figure 7 is a block diagram of a low noise modulator of the breaker type. Figure 8 is a block diagram of a first implementation of a wake-up using the concepts of the invention. Figure 9 is a block diagram of a second implementation of a wake-up using the concepts of the invention. Figure 10 is a block diagram of a third implementation of a wake-up using the concepts of the invention. Figure 11 is a block diagram of a preferred embodiment of a disturber using the concepts of the invention. Figure 12 is a spectral diagram of the disturber described in Figure 11. Figure 13 shows implementations of the first and second low pass filters of the invention. SUMMARY The present invention is directed to a method and system for awakening disturbed audio signals with the frequency change that meets the needs described above. The invention includes a method and a system for awakening disturbed audio signals with changed frequency. The described system of wakefulness aroused a disturbed frequency, transferring audio information signals, generating a modulation carrier signal at a frequency that falls outside the spectral range of the original frequency of a disturbed audio signal of approximately 50 Hz to approximately 15 Khz, first generating a first modulation carrier signal having a frequency greater than the highest frequency in the original audio signal. This first modulation carrier is used to modulate the double sideband of the disturbed audio signal at a first modulation frequency, a first upper sideband signal and a first lower sideband signal. This set of signals is filtered by a filter to filter the first modulation frequency, all its harmonics, and the upper sideband signal and its harmonics of the double sideband signal, and pass the first lower sideband signal. A second modulation carrier frequency having a frequency lower than the first modulation frequency is generated. This second modulation frequency is connected to a second modulation element for modulating the double sideband, the first lower sideband signal with the second modulation carrier frequency to produce a second modulation frequency, a second higher sideband signal and a second lower sideband signal. A second filter passes the second lower sideband signal to produce an awakened audio signal. The modulators used are modulators of the noise switch type low that improve the ratio of signal to noise in the signal awakened on the linear modulators used previously. The use of switch type modulators provides a lower cost device with improved performance. An accompanying disturbance device uses similar techniques to provide improved performance at a lower cost. The method for disturbing an original audio signal from about 50 Hz to about 15 Khz includes: Generating a first modulation carrier signal having a frequency greater than the highest frequency in the original audio signal; modulating the quadrature of the original audio signal in a first lower sideband signal; filtering the first modulation frequency and all the harmonics, at least part of the upper side band signal and all the harmonics of the modulated signal, and passing the first lower sideband signal; generating a second modulation carrier frequency having a frequency greater than the first modulation frequency; modulating the double sideband, the first lower sideband signal with the second modulation carrier frequency to produce a second modulation frequency, a second upper sideband signal and a second lower sideband signal; filtering the second modulation frequency, part of the second upper sideband signal and the second lower sideband signal to pass the second lower sideband signal to produce a disturbed audio signal. From the point of view of the method, the invention broadly includes moving the frequency of the original spectrum of the audio information signals to produce disturbed audio information signals, generating a modulation carrier signal having a frequency that falls outside of the frequency spectral range of the audio information signals, and the first single sideband modulation followed by the modulation of the double sideband of the original information signals with the modulation carrier signal to translate the signal frequency of original audio information at a given address. Preferably, the frequency of the signal or the modulation carrier signals are varied during generation in a pseudo-random manner, particularly by sweeping the frequency of the modulation carrier signal between predetermined limits. The step of varying the frequency of the modulation carrier signal preferably includes the steps of starting an operation of varying the frequency in response to a first control signal at a rate determined by a second control signal. For a more complete understanding of the nature and advantages of the invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings. DESCRIPTION Figure 5 shows a block diagram, 'and Figure 6 shows a spectral diagram of the preferred embodiment of the present description. Figure 6a shows the spectral characteristics of the disturbed audio input of the preferred embodiment. This shows the disturbed audio offset by a displacement frequency determined by the disturbance process. Figure 6b shows the relation of a first carrier of the mixer and the output of the first mixer. Both the upper and lower sideband and the residual carrier fA plus the harmonics of all these are in the first output of the mixer. Figure 6c shows the filter characteristics of the first low pass filter following the first output of the mixer. It is crucial that this first low pass filter filter the residual carrier and its harmonics from the upper sideband. Figure 6d shows the output of the spectral characteristics of the output of the first low pass filter following the first output of the mixer. Figure 6e shows the relationship of the second carrier with the output of the first low pass filter to form the last wake-up step. Figure 6f shows the ratio of the awakened audio that has passed through a second low pass filter with a cut of 12 Khz to filter fb and its upper sideband on top of fB with the absence of the whistle frequency component (fa -fb). The component of the whistle frequency (fa-fb is typically equal to or less than -85 decibels in the awakened audio.) In this preferred embodiment, fA is approximately 19 Khz and fB is approximately 16.4 Khz., because with these frequencies the first low pass filter can be designed cheaply. If increased operation is desired at a higher cost, the carrier frequencies may be higher to minimize the escape of the components of the disturbed audio input, so as not to interfere with the output of the lower sideband of the first mixer. Note that in Figures 6a and 6b there is an overlap between the spectra of the lower-sideband frequencies and the disturbed audio frequencies. If the first mixer feeds enough of the disturbed audio, distortion products will appear at the awakened output. Setting the carrier frequencies to, for example, fA = 39 Khz and fB = 36.4 Khz, the escape of the disturbed input will not cause distortion products in the wake-up output, since they will not overlap with the lower sideband of the first mixer , that is, 36.4 Khz at 24 Khz against 2.6 Khz at 14.6 Khz from the disturbed entrance. However, raising fA and fB twice causes the inclination of the first low pass filter to increase to approximately twice. This would require higher order filters, such as a 10-pole elliptical low-pass filter. Minimum carrier leakage and disturbed audio leakage with lower impulse noise is achieved using a double-pole single-pole analog switch such as 74 HCT 4053, or its equivalent, ie switch-type mixer MC1496, with one input of carrier equal to or more than 350 mv pp. It was found that, for example, with a CD 4053 analog switch, the "on" resistance resulted in an average noise of 2.5 nv / / Hz which resulted in a noise resistance of (/ 4kTBr = VN = 2.5 nv / / Hz, B = 1 Hz, T = 298 ° Kelvin, K = to the Bolzman constant and R = to the noise resistance) of 400 ohms. The "on" resistance of CD 4053 was measured as 440 ohms. Thus it was experimentally found that the "on" resistance of the analog switch (ie, 4053) produces the same amount of noise as a resistor component of the same resistance. Thus, an "on" resistance of 440 ohms on a 4053 CD has essentially the same noise as a 440 ohm resistor. Linear modulators, such as AD 534, produce 0.6 mv RMS over a bandwidth of 10 Khz, or a noise density of 0.6 mv / / 10 Khz = 60 nv / / Hz. Therefore, the AD 534 linear modulator produces approximately 60 / 2.5 more noise than the CD 4053 switch. This is equivalent to an improvement of 27 decibels when a CD 4053 is used on a linear modulator. Gilbert modulators, such as 1496 or 1495, will produce low noise, that is <; 5 nv / / Hz, when the input of the carrier of these devices changes the differential pairs on and off. This is achieved by overheating the input of the carrier with a square-wave carrier input, with a square wave of > = / -200 mv, or a larger sine wave of > 1 v pp. When sine modulators, such as 1495, do not have the overhanded carrier inputs to produce linear modulation, the noise is substantially higher against a modulator 1496 in switch mode. This is because two transistors of differential pairs start amplifying their own noise. The internal base resistance of each transistor is usually approximately 50 to 200 ohms. If one assumes 100 ohm series internal base resistors in the two pairs of differential pair transistors in series in a 1495. and a load of 1 kohm for one output, we additionally assume that each of these transistors has an inactive voltage of a collector current of 1 ma, the output noise is then equal to 1/2 * 1000 (gm) V nr = V0 noise, gm = 38 ma / V for an Ic = 1 ma. Therefore, V nr = / 400 ohm * 4kT = 2.5 nv / Hz. VQ noise = 19 * 2.5 nv / / Hz = 47.5 nv / / Hz, from a 1495 modulator. This is 19 times or 25 decibles more noise than the CD 4053, with an "on" resistance of 440 ohms. It should be noted that the output noise decreases in modulator 1495 or 1496 as the carrier input increases. The key to the preferred mode is the use of a low pass filter (LPF), after the first mixer that rejects a residual carrier from the first mixer and removes the sidebands related to the harmonics of the carrier and the harmonics of the carrier If this is not done, the harmonics of the whisfrequency (3fa-3fb), (5fa-5fb) and etc., will appear in the wake-up output in an audible manner. This first low-pass filter is generally a 7-pole or more elliptical filter, with at least one zero tone for notching the first carrier frequency of the mixer, fA. In practice, the best choice is a 9-pole active filter with general impedance converters for a stable and precise filter. In the preferred embodiment, the short of 3 decibles of the first low pass filter is approximately 17 Khz, with at least one attenuation of 40 decibels at 19 Khz. A detailed description of the preferred embodiment is described below with reference to Figure 5. The wake-up apparatus 12 has a disturbed audio signal input 60, and contains the wake-up process of the preferred embodiment. The disturbed audio 60 enters a first input of a first mixer 63. The second input of this first mixer is a first carrier signal FA generated by the frequency generator A, 61, which is approximately 19 Khz. The output of the first mixer 63 contains the carrier supply through FA, all its sideband components and the harmonics. The output of the mixer 63 is fed to a low pass filter 65 which filters the first carrier, the upper side band and all the harmonics of the signal 60. The output of the low pass filter 65, the signal 66, is fed into a first input of a second mixer 66. The second input of this second mixer is a second carrier signal fB generated by the frequency generator B, 62, which can be 16.4 Khz of 16.4 Khz +/- 100 Hz, changed pseudo-randomly for reasons of security. See U.S. Patent No. 5,095,279 for further explanation of this security process. The output of the second mixer 70 contains the awakened audio of the baseband, the second residual carrier of the components of the upper sideband above the frequency fB. The second low pass filter 71 with a decreased frequency of approximately 12 Khz removes everything above 12 KHz, but the awakened audio signal passes to the output line 23. In the above preferred embodiment, the mixers use a switch-type low pulse modulator, or thermal noise modulator, as described in Figure 7. The operation of this mixer will be described in relation to the first mixer. The second mixer works with the same principle. The disturbed audio signal 60 is fed into the + input of the gain unit amplifier 73. The output of the amplifier 73 is fed on the Vin line 74 to a one-pole double pole input of the analog switch 32. The output of 73 is also fed into the input of the gain unit inversion amplifier consisting of R2a, R2b, and amplifier 65. The output of amplifier 65 is ~ Vin 75, which is fed to a second input of switch 32. first FA carrier frequency is fed into the double pole shift control input, of the single jump switch 32. The double pole switch, and the only jump used is 1/3 of a 74HCT4053 or its equivalent, and is fed the A220 amplifier. The A220 is the output of the mixer. For a minimum carrier leak from the mixer output 65, the zero signal voltage DC, of the two inputs of the switch 32 Vin and -Vin must be exactly the same, that is, Ov. In addition to the inversion amplifier 73, there must be a gain of unit -1 to have a minimum disturbed audio in (Vin) power. Thus, R2a = R2b is required within 1 percent, or better for a broadband operation of amplifier 65 (ie, NE5532). Figure 13 shows a conventional RLC low pass filter with zeros for the first low pass filter of the booster. Because the inductors from L - ^ to L3 are quite large, 2 millihenries up to 20 millihenries to achieve a low cost. These lower cost inductors suffer from an adequate Q in audio frequencies. Much more expensive inductors with higher Q's provide better low-pass filter, but are out of the budget of a low-cost wake-up system. Figure 13b shows a 9-pole elliptical low-pass filter that is not sensitive to the tolerance of the parts as other active filters. This is important, since fa, the first carrier frequency can be filtered by at least one attenuation of -40 decibels. Figure 13b is a General Impedance Converter (FIC) active low pass filter that has been found to provide very high performance for low cost filtering. The capacitors can be cheap 5 percent mylar film capacitors. Resistors are cheap 1 percent resistors, and operation amplifiers can be of the common type, such as TL082, NE5532, etc. Figure 13c shows an example of the second filter as a 7-pole low pass filter. Amplifiers A1000, A2000 and A3000 can be simple voltage trackers of common operation amplifiers or single transistor emission trackers. The second filter in the wake-up device can be any passive or active low-pass filter with sufficient attenuation of the stop band to provide an awakened audio signal without measurable artifacts, such as the second carrier tone, its upper sidebands and / or audible artifacts. Figures 8 to 11 show several implementations using the concepts of the invention. In addition to a wake-up system, as described above, many of the same elements can be used in a disturber to achieve many of the same advantages achieved in the previously described wake-up device, that is, lower impulse noise output and fewer pulse requirements. filter than the previous technique, like that of Forbes ('853). Figure 11 is a block diagram, and Figure 12 is a series of spectral diagrams of a preferred embodiment of the disturber. An audio signal with a spectral response of disturbing 30 Hz up to 15 Khz 91 is fed into a low pass filter 91 to eliminate any unwanted signal below 15 Khz. The output of the low pass filter 92, 93, is connected to the phase changers of all steps of 0 degrees and 90 degrees, 94 and 95. The outputs of the phase changers 94 and 95 in turn connect to the first input of the low noise modulators of switch type 96 and 97. The signal generator 98 generates a square wave signal at approximately 16.4 Khz, with outputs of 0 degrees and 90 degrees which are connected to the second inputs of the modulators 96 and 97. The outputs of the modulators 96 and 97 are summed to produce signal 103, a modulated quadrature signal resulting in a residual carrier of 16.4 Khz with a lower sideband. Figure 12 shows the relationship of the quadrature modulated audio components with the original audio signal 91. This modulated quadrature signal is fed through the low pass filter 104 as the signal 105, and is essentially the same filter as the signal. first filter of the wake-breaker described above. This signal is connected to a first input of a third modulator 106. The modulator 106 is a low-noise or pulse-type modulator, as described above, and is shown in Figure 7. A second frequency of carrier by the square wave oscillator 99 that generates a frequency of approximately 19 Khz, as shown in Figure 12e. The output of the modulator 106 contains a 19 Khz carrier and upper and lower sidebands. This signal is filtered by a low pass filter 107 to produce a disturbed audio signal with a displacement of approximately 2.6 Khz. Theoretically, to diminish the dynamic artifacts caused by changes of frequency of fast passage of the carrier of 16.4 Khz, so much in the disturber as in the alarurbador, the Filters of Low Pass that follow the first mixer of quadrature, as much of the disturber as of the alarurbador , respectively, should be almost identical in group delay responses (passing responses). If the transient response characteristics of the Low Pass filters are different from the transient characteristics of the wake up device, the changes of the 16.4 Khz carrier step have to be made slower to reach the minimum wakefulness devices. It is preferred to have faster step changes in the security carrier (16 Khz +/- 100 Hz), and to have the first low pass filter in the wake-up device with the same characteristics as the filter 104 in the disturber of Figure 11. In addition, the second low-pass filter in the wake-up device should have the same characteristics of the filter 107 of the disturber of Figure 11. This allows the base change spectrum of the disturber to be quickly tracked in the wake-up device without the artefacts caused by the biases of the delay of time between him disturbing and the alarurbador that they crawl. stepped deviations of 16 Khz. It should be noted that all carriers for all mixers in this invention for wake-up and disturbance should preferably be square-wave signals for minimum artifacts. Although the foregoing provides a complete description of the preferred embodiment of the invention, those skilled in the art will be able to make different modifications, alternative constructions and equivalents. However,

Claims (50)

1. previous descriptions and the illustrations are not to be considered as limiting the scope of the invention, which is defined by the appended claims. NOVELTY OF THE INVENTION Having described the foregoing invention, it is considered as a novelty and, therefore, property is claimed as contained in the following: REVIVAL ICONS 1. A system for awakening an audio information signal translated to frequency disturbed, generating a modulation carrier signal at a frequency that falls outside the spectral range of the original frequency of an original audio signal of about 50 Hz to about 15 Khz, which includes: An element for generating a first signal carrier modulation that has a higher frequency than the highest frequency in the original audio signal; a modulation element for modulating the double sideband of the disturbed audio signal at a first modulation frequency, a first upper sideband signal and a first lower sideband signal; a first filter element for filtering the first modulation frequency, all its harmonics, the upper sideband signal and its harmonics of the double sideband signal, and passing the first lower sideband signal; an element for generating a second modulation carrier frequency having a frequency lower than the first modulation frequency; a second modulation element for modulating the double sideband, the first lower sideband signal with the second modulation carrier frequency for producing a second modulation frequency, a second upper sideband signal and a second lower sideband signal; an element for filtering to pass the second lower sideband signal to produce an awakened audio signal.
2. 2. A system according to claim 1, wherein the element for generating the first and second modulation carriers includes square wave generators.
3. 3. A system according to claim 1, wherein the first modulation element and the second modulation element include low noise modulators of the switch type.
4. 4. A system according to claim 1, wherein the first filter element includes an elliptical filter containing at least seven poles and a zero for notching the first carrier frequency.
5. A system according to claim 1, wherein the first filter element includes an active filter that contains at least seven poles with general impedance converters.
6. 6. A system according to claim 1, wherein the second filter element includes a filter with seven or more poles.
7. 7. A system according to claim 1, wherein the first modulation carrier generates a frequency of at least 19 Khz.
8. A system according to claim 1, wherein the second modulation carrier generates a frequency of at least 500 Hz below the frequency of the first modulation frequency.
9. 9. A system according to claim 8, wherein the second modulation carrier is varied pseudo-randomly and approximately +/- 100 Hz.
10. A system according to claim 3, wherein the first and second low noise modulators of the switch type include modulators MC 1496.
11. 11. A system according to claim 3, wherein the first low noise modulator of switch type includes an analog switch coupled with inverse polarities of the disturbed audio input signal.
12. 12. A system according to claim 3, wherein the second switch-type low noise modulator includes an analog switch coupled with a positive polarity and a negative polarity of the first lower side base signal.
13. 13. A method for awakening signals of single sideband audio information translated from the disturbed frequency spectrum, generating a modulation carrier signal at a frequency that falls outside the spectral range of the original frequency of an original audio signal of approximately 50 Hz to approximately 15 Khz, including this method the steps of; Generating a first modulation carrier signal having a frequency greater than the highest frequency in the original audio signal; modulating the double sideband of the disturbed audio signal at the first modulation frequency, a first upper sideband signal and a first lower sideband signal; filtering the first modulation frequency, all its harmonics, the upper sideband signal, and all its harmonics and all the harmonics of the lower sideband signal of the double sideband signal, and passing the lower sideband signal; generating a second modulation carrier frequency having a frequency lower than the first modulation frequency; modulating the double sideband of the first lower sideband signal with the second modulation carrier frequency to produce a second modulation frequency, a second upper sideband signal and a second lower sideband signal; filtering the second modulation frequency, a second upper sideband signal to pass the second lower sideband signal to produce an awakened audio signal.
14. 14. A method according to claim 13, wherein the element for generating the first and second modulation carriers includes square wave generators.
15. 15. A method according to claim 13, wherein the dual sideband modulators include low noise modulators of the switch type.
16. 16. A method according to claim 13, wherein the filtering of the first modulation frequency and all its harmonics, the upper sideband signal and all the harmonics of the dual sideband signal, and the pitch of the Lower sideband signal uses an elliptical filter that contains at least seven poles and zero tuning to display the first carrier frequency.
17. 17. A method according to claim 13, wherein the filtering of the first modulation frequency and all its harmonics, the upper sideband signal and all the harmonics of the double sideband signal, and the passing of the signal The lower sideband uses an active filter that contains at least seven poles with general impedance converters.
18. 18. A method according to claim 13, wherein the second filtering of the second modulation frequency, an upper sideband signal and a lower sideband signal includes a filter of seven or more poles.
19. 19. A method according to claim 13, wherein the first modulation carrier generates a frequency of at least 19 Khz.
20. 20. A method according to claim 13, wherein the second modulation carrier generates a lower frequency than the first modulation carrier by at least 500 Hz.
21. 21. A method according to claim 13, wherein the second modulation carrier generates a frequency of approximately 2.6 Khz less than the first modulation carrier.
22. 22. A method according to claim 13, wherein the second modulation carrier generates a frequency that varies pseudo-randomly.
23. 23. A method according to claim 15, wherein the first and second pulse-type low pulse noise modulators include switched Gilbert multipliers.
24. 24. A method in accordance with the claim 15, wherein the first low noise modulator type includes an analog switch coupled with a positive polarity and a negative polarity of the disturbed audio input signal.
25. 25. A method in accordance with the claim 16, wherein the second low pulse type noise modulator includes an analog switch coupled with a positive polarity and a negative polarity of the first lower sideband signal.
26. 26. A method of compliance with the claim 15, wherein the first low noise modulators of the switch type include periodic switch modulators.
27. 27. A method of compliance with the claim 16, wherein the second switch-type low pulse noise modulators include periodic switch modulators.
28. 28. A system for disturbing the original audio signal from about 50 Hz to about 15 Khz including: An element for generating a modulation carrier signal having a frequency greater than the highest frequency in the original audio signal; a first modulation element for modulating the quadrature sideband of the original audio signal in a first lower sideband signal; a first filter element for filtering the first modulation frequency, and at least a majority of its harmonics, the upper sideband signal and its harmonics of the quadrature signal, and passing the first lower sideband signal; an element for generating a second modulation carrier frequency having a frequency higher than the first modulation frequency; a second modulation element for modulating the double sideband, the first lower sideband signal with the second modulation carrier frequency for producing a second modulation frequency, a second upper sideband signal and a second lower sideband signal; an element for filtering to pass the second lower sideband signal to produce a disturbed audio signal.
29. 29. A system according to claim 28, wherein the element for generating the first and second modulation carriers includes a square wave generator.
30. 30. A system according to claim 28, wherein the second modulation element includes noise modulators under the switch type.
31. 31. A system according to claim 26, wherein the first filter element includes an elliptical filter that contains at least seven poles.
32. 32. A system according to claim 28, wherein the first filter element includes a filter without having to be tuned out of the first frequency.
33. 33. A system according to claim 28, wherein the first filter element includes an active filter that contains at least seven poles with general impedance converters.
34. 34. A system according to claim 28, wherein the second filter element includes a filter of seven or more poles.
35. 35. A system according to claim 28, wherein the first modulation carrier generates a frequency of at least 16.4 Khz.
36. 36. A system according to claim 28, wherein the second modulation carrier generates a frequency of at least 500 Hz above the first modulation carrier.
37. 37. A system according to claim 26, wherein the second modulation carrier generates a frequency that varies pseudo-randomly and approximately +/- 100 Hz.
38. 38. A system according to claim 28, wherein the low noise modulator. The switch type includes a modulator of a balanced differential torque type modulator.
39. 39. A system according to claim 28, wherein the second switch type noise modulator includes an analog switch coupled with inverted polarities of the first upper sideband signal.
40. 40. A method for disturbing an original audio signal from about 50 Hz to about 15 Khz, the method including the steps of: Generating a first modulation carrier signal having a frequency greater than the highest frequency in the audio signal original; quadrature modulating the original audio signal in a first lower sideband signal; filtering the first modulation frequency and all its harmonics, the upper sideband signal and all the harmonics of the modulated signal, and passing the first lower sideband signal; generating a second modulation carrier frequency having a frequency greater than the first modulation frequency; modulating the double sideband of the first lower sideband signal with the second modulation carrier frequency to produce a second modulation frequency, a second upper sideband signal and a second lower sideband signal; filtering the second modulation frequency, the second upper sideband signal and the second lower sideband signal to pass the second lower sideband signal to produce a disturbed audio signal.
41. 41. A method according to claim 40, wherein the first and second modulation carrier generators include square wave generators.
42. 42. A method according to claim 40, wherein the dual sideband modulator includes a low noise modulator type switch.
43. 43. A method according to claim 40, wherein filtering the first modulation frequency and all its harmonics, the upper sideband signal and all the harmonics of the dual sideband signal and passing the sideband signal. lower; uses an elliptical filter that contains at least seven poles and a zero-tone notch tuned to display the first carrier frequency.
44. 44. A method according to claim 40, wherein filtering the first modulation frequency and all its harmonics, the upper sideband signal and all the harmonics of the dual sideband signal and passing the sideband signal. lower, uses an active filter that contains at least seven poles with general impedance converters.
45. 45. A method according to claim 40, wherein the second filtering of the second modulation frequency, a second upper sideband signal and a second lower sideband signal includes a filter of seven or more poles.
46. 46. A method according to claim 40, wherein the first modulation carrier generates a frequency of at least 16.4 Khz.
47. 47. A method according to claim 46, wherein the second modulation carrier generates a frequency of at least 60 Hz greater than the first modulation carrier frequency.
48. 48. A method according to claim 40, wherein the second modulation carrier generates a frequency that varies pseudo-randomly and approximately a frequency substantially equal to 19 Khz.
49. 49. A method according to claim 40, wherein the low noise modulator of the switch type includes a balanced multiplier, differential pair modulator.
50. 50. A method according to claim 40, wherein the low noise modulator of the switch type includes an analog switch coupled with a positive polarity and a negative polarity of the upper sideband signal. &? testimony ás what fimo antarior this city of Hexico, O.f ,, at 25 days if saas de dctubrs gives U34. Roa MAcaoVISiON CORPORATIo Ing, Javier Saucedo C.