Method and system for speech compression

Claim 5

A method of transmitting a speech signal as recited in claim 2 wherein said step of regenerating the second formant includes modulating the baseband signal to provide a double sideband signal and passing only the lower sideband signal to be combined with the baseband signal.

Claim 6

A method of transmitting a speech signal as recited in claim 3 and further comprising the steps of transmitting a fricative parameter of the speech signal, generating a synthetic noise burst signal in accordance with the fricative parameter and combining the noise burst signal with the baseband parameter and the regenerated second formant to produce the speech signal.

Claim 7

A method of transmitting a speech signal as recited in claim 3 wherein said baseband signal represents the band of frequencies from 200 to 1,000 Hz.

Claim 8

A method of transmitting a speech signal as recited in claim 3 wherein said baseband signal represents the band of frequencies from 300 to 700 Hz.

Claim 9

A method of transmitting a speech signal as recited in claim 3 wherein the one harmonic is within a range of from 2,200 to 2, 800Hz.

Claim 10

A method of transmitting a speech signal as recited in claim 3 wherein the one harmonic is within a range of from 2,400 to 2, 600Hz.

Claim 11

A speech compression system comprising a speech source providing a speech signal having first and second formants; filter means for passing a baseband signal of said speech signal including said first formant; means for transmitting said baseband signal; means for receiving said baseband signal; signal combining means for producing a reconstructed speech signal; means supplying said baseband signal from said receiving means to said signal combining means; and means receiving said baseband signal from said receiving means for generating at least one Harmonic of the pitch frequency and processing said at least one harmonic with said baseband signal to regenerate said second formant and supply said regenerated second formant to said signal combining means whereby said reconstructed speech signal includes said first formant and said regenerated second formant.

Claim 12

A speech compression system comprising a speech source providing a speech signal having first and second formants; filter means for passing a baseband signal of said speech signal including said first formant; means for transmitting said baseband signal; means for receiving said baseband signal; signal combining means for producing a reconstructed speech signal; means supplying said baseband signal from said receiving means to said signal combining means; and means receiving said baseband signal from said receiving means for generating at least one Harmonic of the pitch frequency and processing said at least one harmonic with said baseband signal to regenerate said second formant and supply said regenerated second formant to said signal combining means whereby said reconstructed speech signal includes said first formant and said regenerated second formant.

Claim 13

A speech compression system comprising a speech source providing a speech signal having first and second formants; filter means for passing a baseband signal of said speech signal including said first formant; means for transmitting said baseband signal; means for receiving said baseband signal; signal combining means for producing a reconstructed speech signal; means supplying said baseband signal from said receiving means to said signal combining means; and means receiving said baseband signal from said receiving means for regenerating said second formant from said baseband signal and supplying said regenerated second formant to said signal combining means including means for processing said baseband signal to produce harmonics of the pitch frequency of said speech signal, means for isolating at least one of said harmonics, and means for modulating said at least one harmonic with said baseband signal to regenerate said second formant harmonically related to said baseband signal whereby said reconstructed speech signal includes said first formant and said regenerated second formant.

Claim 14

A speech compression system comprising a speech source providing a speech signal having first and second formants; filter means for passing a baseband signal of said speech signal including said first formant; means for transmitting said baseband signal; means for receiving said baseband signal; signal combining means for producing a reconstructed speech signal; means supplying said baseband signal from said receiving means to said signal combining means; and means receiving said baseband signal from said receiving means for regenerating said second formant from said baseband signal and supplying said regenerated second formant to said signal combining means including means for processing said baseband signal to produce harmonics of the pitch frequency of said speech signal, means for isolating at least one of said harmonics, and means for modulating said at least one harmonic with said baseband signal to regenerate said second formant harmonically related to said baseband signal whereby said reconstructed speech signal includes said first formant and said regenerated second formant.

Claim 15

A speech compression system as recited in claim 10 wherein said isolating means includes a narrowband filter having a center frequency within the range of from 2,200 to 2,800 Hz.

Claim 16

A speech compression system as recited in claim 10 wherein said isolating means includes a narrowband filter having a center frequency substantially at 2,500 Hz.

Claim 17

A speech compression system as recited in claim 12 wherein said processing means is a half wave rectifier, said modulating means is a balanced modulator providing a double sideband signal and said means for regenerating said second formant further includes a low pass filter for passing the lower sideband signal from said balanced modulator to said signal combining means.

Claim 18

A speech compression system as recited in claim 13 wherein said speech signal includes unvoice sounds and further comprising means for detecting said unvoice sounds and generating a fricative parameter corresponding thereto and means responsive to the received fricative parameter for synthetically generating a noise burst signal and supplying said noise burst signal to said signal combining means whereby said reconstructed speech signal includes said first formant, said regenerated second formant and said noise burst signal.

Claim 19

A speech compression system as recited in claim 10 wherein said speech signal includes unvoice sounds and further comprising means for detecting said unvoice sounds and generating a fricative parameter corresponding thereto and means responsive to the received fricative parameter for synthetically generating a noise burst signal and supplying said noise burst signal to said signal combining means whereby said reconstructed speech signal includes said first formant, said regenerated second formant and said noise burst signal.

Claim 20

A receiver for reconstructing a speech signal represented by a frequency band signal comprising means for receiving said frequency band signal; means receiving said frequency band signal from said receiving means for processing said frequency band signal to produce harmonics of said frequency band signal; means for isolating at least one of said harmonics; means for modulating said at least one harmonic with said frequency band signal to produce a modulated signal; and signal combining means receiving said frequency band signal from said receiving means and said modulated signal from said modulating means for combining said frequency band signal and said modulated signal to produce a reconStructed speech signal.

Claim 21

A receiver for reconstructing a speech signal represented by a frequency band signal comprising means for receiving said frequency band signal; means receiving said frequency band signal from said receiving means for processing said frequency band signal to produce harmonics of said frequency band signal; means for isolating at least one of said harmonics; means for modulating said at least one harmonic with said frequency band signal to produce a modulated signal; and signal combining means receiving said frequency band signal from said receiving means and said modulated signal from said modulating means for combining said frequency band signal and said modulated signal to produce a reconStructed speech signal.

Claim 22

A receiver as recited in claim 16 wherein said modulating means includes a balanced modulator providing a double sideband signal and low pass filter means for passing the lower sideband signal to said signal combining means as said modulated signal.

Claim 23

A receiver as recited in claim 17 wherein said isolating means includes a narrowband filter having a center frequency within the range of from 2,200 to 2,800 Hz.