System for frequency modification of speech and other audio signals

Claim 2

A processing system for frequency modification of a speech or other original audio signal, which retains the time span of the original signal, comprising: analog-digital converter means for converting an original audio signal to a digital data signal; two temporary serial storage means, each having a capacity of n digits, where n is a positive integer greater than or equal to 32; recording means for alternately recording said digital data signal in said two storage means at a primary bit rate f1; readout means for reading out said digital data signal from said storage means, in groups of digits taken alternately from said two storage means, at a secondary bit rate f2 substantially different from f1, to develop an output signal; synchronizing means for actuating said recording means and said readout means at time intervals recurring at a frequency f3, where f3 is approximately equal to f2/2n in the range of 10 to 100 hz; and output means, comprising a digital-analog converter, for utilizing said output signal to develop a processed audio signal with a frequency modification of f1/f2 but having the same time span as the original audio signal.

Claim 3

A processing system for frequency modification of a speech or other original audio signal which retains the time span of the original signal, comprising: first temporary serial storage means, having a capacity of n digits, where n is a positive integer greater than or equal to 32; second temporary serial storage means also having a capacity of n digits; a first clock signal source for developing a first clock signal of frequency f1; a second clock signal source for developing a second clock signal of frequency f2, f2 being substantially different from frequency f1; an analog-digital converter; means for applying an original audio signal to said converter to develop a digital data signal; means for supplying the digital data signal to the inputs of both of said temporary storage means; clock gate means for applying said first and second clock signals to said temporary storage means, in alternation, to store said digital data signal therein at rate f1 and to read out said digital data signal therefrom at rate f2; output gate means for alternately coupling the outputs of said temporary stores to a single output circuit; gate actuation means, comprising a frequency divider with a division ratio of approximately 1/2n, having an input coupled to said second clock signal source and having an output coupled to both said gate means, for developing and supplying to both said gate means an actuating having a frequency f3, where f3 is approximately equal to f2/2n, so that said output circuit always receives said digital data read out at rate f2; and a digital-analog converter, connected to the output gate means, for developing a regenerated speech signal with a frequency change ratio of f1/f2 but within the same time span as the original audio signal.

Claim 4

A processing system for frequency modification of a speech or other original audio signal which retains the time span of the original signal, comprising: first temporary serial storage means, having a capacity of n digits, where n is a positive integer greater than or equal to 32; second temporary serial storage means also having a capacity of n digits; a first clock signal source for developing a first clock signal of frequency f1; a second clock signal source for developing a second clock signal of frequency f2, f2 being substantially different from frequency f1; an analog-digital converter; means for applying an original audio signal to said converter to develop a digital data signal; means for supplying the digital data signal to the inputs of both of said temporary storage means; clock gate means for applying said first and second clock signals to said temporary storage means, in alternation, to store said digital data signal therein at rate f1 and to read out said digital data signal therefrom at rate f2; output gate means for alternately coupling the outputs of said temporary stores to a single output circuit; gate actuation means, comprising a frequency divider with a division ratio of approximately 1/2n, having an input coupled to said second clock signal source and having an output coupled to both said gate means, for developing and supplying to both said gate means an actuating having a frequency f3, where f3 is approximately equal to f2/2n, so that said output circuit always receives said digital data read out at rate f2; and a digital-analog converter, connected to the output gate means, for developing a regenerated speech signal with a frequency change ratio of f1/f2 but within the same time span as the original audio signal.

Claim 5

An audio signal processing system according to claim 2 in which said actuating signal frequency f3 is in the range of 10 to 100 hz.

Claim 6

An audio signal processing system according to claim 2 in which said a actuating signal frequency f3 is approximately 33 hz.

Claim 7

An audio signal processing system according to claim 4 in which the value of n is greater than 500.

Claim 8

An audio signal processing system according to claim 4 in which the value of n is a power of two.

Claim 9

An audio signal processing system according to claim 4 in which the value of n is a power of two exceeding 29.

Claim 10

An audio signal processing system according to claim 2 in which said analog-digital converter is a delta modulator driven by the first clock signal f1.

Claim 11

A processing system for frequency modification of an audio-frequency analog signal which retains the same time span as the original signal, comprising: a first temporary serial storage means, having a capacity of n digits, where n is a positive integer greater than or equal to 32; a second temporary serial storage means, also having a capacity of n digits and having its input stage connected to the output stage of said first temporary storage means; a recording clock signal source for developing a recording clock signal of frequency f1; a readout clock signal source for developing a readout clock signal of frequency f2, f2 being substantially different from frequency f1; a transfer clock signal source for developing a transfer clock signal of frequency f4 such that f4 is very much greater than f1 and f4 is very much greater than f2; an analog to digital converter; means for applying an original audio-frequency analog signal to said converter to develop a digital data signal; means for supplying the digital data signal to the input of said first temporary storage means; clock input gate means for alternately applying said recording and transfer clock signals to said first temporary storage means, and for alternatively applying said readout and transfer clock signals to said second temporary storage means; a digital-analog converter; output gate means for coupling the output of said second temporary storage means to said digital analog converter; and gate actuation means for developing a gate actuation signal of a frequency f3, where f3 is approximately equal to f2/2n and is lower than f1, and for applying said gate actuation sIgnal to actuate both said gate means, applying said transfer clock signal to both said storage means and cutting off the input to said digital-analog converter periodically at frequency f3 to enable said digital-analog converter to develop a regenerated speech signal with a frequency change ratio of f1/f2 but within the same time span as the original audio signal.

Claim 12

A processing system for frequency modification of an audio-frequency analog signal which retains the same time span as the original signal, comprising: a first temporary serial storage means, having a capacity of n digits, where n is a positive integer greater than or equal to 32; a second temporary serial storage means, also having a capacity of n digits and having its input stage connected to the output stage of said first temporary storage means; a recording clock signal source for developing a recording clock signal of frequency f1; a readout clock signal source for developing a readout clock signal of frequency f2, f2 being substantially different from frequency f1; a transfer clock signal source for developing a transfer clock signal of frequency f4 such that f4 is very much greater than f1 and f4 is very much greater than f2; an analog to digital converter; means for applying an original audio-frequency analog signal to said converter to develop a digital data signal; means for supplying the digital data signal to the input of said first temporary storage means; clock input gate means for alternately applying said recording and transfer clock signals to said first temporary storage means, and for alternatively applying said readout and transfer clock signals to said second temporary storage means; a digital-analog converter; output gate means for coupling the output of said second temporary storage means to said digital analog converter; and gate actuation means for developing a gate actuation signal of a frequency f3, where f3 is approximately equal to f2/2n and is lower than f1, and for applying said gate actuation sIgnal to actuate both said gate means, applying said transfer clock signal to both said storage means and cutting off the input to said digital-analog converter periodically at frequency f3 to enable said digital-analog converter to develop a regenerated speech signal with a frequency change ratio of f1/f2 but within the same time span as the original audio signal.

Claim 13

A processing system for frequency modification of an audio signal, according to Claim 9, in which the time during which said transfer clock signal is applied to said storage means, in each cycle of said gate actuation signal, is much smaller than the time during which said recording and readout clock signals are supplied thereto.

Claim 14

A processing system system for frequency modification of an audio signal, according to Claim 9, in which f3 is in the range of 10-100 hz.

Claim 15

A processing system for frequency modification of a speech or other original audio signal, which retains the time span of the original signal, comprising: analog-digital converter means for converting an original audio signal to a digital data signal; first temporary serial storage means, having a capacity of n digits, where n is a positive integer greater than or equal to 32; recording means for recording said digital data signal in said first temporary serial storage means at a primary bit rate f1; second temporary serial storage means also having a capacity of n digits, and, having an input connected to the output of said first temporary serial storage means; transfer means for transferring said digital data signal from said first storage means to said second storage means, at a transfer rate f4 very much higher than rate f1; readout means for reading out said digital data signal from said second storage means at a secondary bit rate f2 substantially different from f1 and very much lower than f4, to develop an output signal; synchronizing means for actuating said transfer means and for interrupting said recording means and said readout means, at time intervals recurring at a frequency f3, where f3 is approximately equal to f2/2n in the range of 10 to 100 hz, said time intervals being very much smaller than 1/f3; and output means, comprising a digital-analog converter, for utilizing said output signal to develop a processed audio signal with a frequency modification of f1/f2 but having the same time span as the original audio signal.

Claim 16

A processing system for frequency modification of a speech or other original audio signal, which retains the time span of the original signal, comprising: analog-digital converter means for converting an original audio signal to a digital data signal; first temporary serial storage means, having a capacity of n digits, where n is a positive integer greater than or equal to 32; recording means for recording said digital data signal in said first temporary serial storage means at a primary bit rate f1; second temporary serial storage means also having a capacity of n digits, and, having an input connected to the output of said first temporary serial storage means; transfer means for transferring said digital data signal from said first storage means to said second storage means, at a transfer rate f4 very much higher than rate f1; readout means for reading out said digital data signal from said second storage means at a secondary bit rate f2 substantially different from f1 and very much lower than f4, to develop an output signal; synchronizing means for actuating said transfer means and for interrupting said recording means and said readout means, at time intervals recurring at a frequency f3, where f3 is approximately equal to f2/2n in the range of 10 to 100 hz, said time intervals being very much smaller than 1/f3; and output means, comprising a digital-analog converter, for utilizing said output signal to develop a processed audio signal with a frequency modification of f1/f2 but having the same time span as the original audio signal.