Abstract This invention relates to a system for audibly recognizing a received signal aurally unclassifiable because of its improper (not clearly bearable) time duration and/or the frequency band occupied thereby. The received signal may be a carrier wave, modulated in amplitude and phase in accordance with the amplitude and phase of a signal to be recognized. In such case, the system includes modulator means for deriving quadrature base-band signal components. The system also includes a signal-storage device, such as a signal recorder movable at one speed during storage of a received signal thereon and at a different speed during retrieval of the signal therefrom, and means for storing the quadrature signal components in the storage device as received. The detected signal is thus translated in frequency on readout, then further processed to derive two control signals: one to vary a VCO whose audible output is representative of the original signal; the other control signal to amplitude-modulate the output of the Voltage-Controlled Oscillator.
A system for audibly recognizing a received signal aurally unclassifiable because of its improper time duration and/or the frequency band occupied thereby comprising: a signal-storage device; means for storing the signal in said device as received; means for retrieving the signal from said device at a time-rate differing from the storing rate; means for developing a control signal varying in magnitude with the weighted instantaneous frequency of said retrieved signal; and an adjustable-frequency audible-tone generator responsive to said control signal; said generator having an output circuit effective to supply an audible signal representative of the received signal.
Claim 2
Independent Claim
97 words
A system for audibly recognizing a received signal aurally unclassifiable because of its improper time duration and/or the frequency band occupied thereby comprising: a signal-storage device; means for storing the signal in said device as received; means for retrieving the signal from said device at a time-rate differing from the storing rate; means for developing a control signal varying in magnitude with the weighted instantaneous frequency of said retrieved signal; and an adjustable-frequency audible-tone generator responsive to said control signal; said generator having an output circuit effective to supply an audible signal representative of the received signal.
Claim 3
Dependent Claim
47 words
A system for audibly recognizing an aurally unclassifiable received signal in accordance with claim 1 in which said signal-storage device is a multi-speed signal recorder movable at one speed during storage of a received signal thereon and at a different speed during retrieval of said signal therefrom.
Claim 4
Dependent Claim
60 words
A system for audibly recognizing an aurally unclassifiable received signal in accordance with claim 1 in which the received signal is a carrier wave modulated in amplitude and phase in accordance with the amplitude and phase of a signal to be recognized and which includes modulator means for deriving quadrature base-band signal components therefrom which are stored in said device.
Claim 5
Dependent Claim
42 words
A system for audibly recognizing an aurally unclassifiable received signal in accordance with claim 3 which includes means for deriving from said signal components a signal representative of the instantaneous frequency of said retrieved signal from which said control signal is derived.
Claim 6
Dependent Claim
56 words
A system for audibly recognizing an aurally unclassifiable received signal in accordance with claim 3 which includes means for deriving from said signal components a second control signal representative of the amplitude of said retrieved signal and means responsive to said second control signal for varying the amplitude of the audible-tone signal output of said generator.
Claim 7
Dependent Claim
25 words
A system for audibly recognizing an aurally unclassifiable received signal in accordance with claim 1 in which said audible-tone generator is a voltage-responsive variable-frequency oscillator.