GB724478A - Compressed frequency communication system - Google Patents

Compressed frequency communication system

Info

Publication number
GB724478A
GB724478A GB12296/53A GB1229653A GB724478A GB 724478 A GB724478 A GB 724478A GB 12296/53 A GB12296/53 A GB 12296/53A GB 1229653 A GB1229653 A GB 1229653A GB 724478 A GB724478 A GB 724478A
Authority
GB
United Kingdom
Prior art keywords
voiced
channel
sounds
cycles
unvoiced sounds
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB12296/53A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Publication of GB724478A publication Critical patent/GB724478A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L25/00—Speech or voice analysis techniques not restricted to a single one of groups G10L15/00 - G10L21/00
    • G10L25/93—Discriminating between voiced and unvoiced parts of speech signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/66—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for reducing bandwidth of signals; for improving efficiency of transmission

Abstract

724,478. Multiplex transmission. STANDARD TELEPHONES & CABLES, Ltd. May 4, 1953 [May 22, 1952], No. 12296/53. Drawings to Specification. Class 40 (4). Speech is transmitted over a channel 1 kilocycle wide by selecting two sub-bands corresponding to voiced and unvoiced sounds, e.g. 200-1200 and 1800-2800 cycles, shifting one or both sub-bands so that both occupy the same frequency range and transmitting them together with an identifying signal for controlling the restoration at the receiving end. A 3-channel system is described using channels 200-1200, 1800-2800 and 2800-3800 cycles. On channel 1, the voiced sounds (i.e. vowels and consonants like L, M, N) are sent unchanged, while unvoiced sounds (such as T, K, P) are shifted in frequency. On channel 2, the voiced sounds are shifted and the unvoiced sounds are unchanged. On channel 3 both are shifted but by different amounts. These results are effected by a switching relay which is controlled by a detector according as the instantaneous input consists of voiced or unvoiced sounds. The detector also controls an oscillator to send an identifying signal, e.g. 1290 or 1360 cycles for channel 1, and other frequencies within the range 1200-1800 cycles for channels 2 and 3. These signals are extracted at the receiver and control relays which in turn control frequencychanging apparatus for reconstituting the speech band. Several forms of detector are described depending on the different frequencies of voiced and unvoiced sounds and on the fact that voiced sounds are periodic and unvoiced sounds aperiodic.
GB12296/53A 1952-05-22 1953-05-04 Compressed frequency communication system Expired GB724478A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US289344A US2810787A (en) 1952-05-22 1952-05-22 Compressed frequency communication system

Publications (1)

Publication Number Publication Date
GB724478A true GB724478A (en) 1955-02-23

Family

ID=23111125

Family Applications (1)

Application Number Title Priority Date Filing Date
GB12296/53A Expired GB724478A (en) 1952-05-22 1953-05-04 Compressed frequency communication system

Country Status (2)

Country Link
US (1) US2810787A (en)
GB (1) GB724478A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3247322A (en) * 1962-12-27 1966-04-19 Allentown Res And Dev Company Apparatus for automatic spoken phoneme identification
US4315105A (en) * 1976-11-23 1982-02-09 Miller Iii Herman P Narrow band transmission system and method

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2941038A (en) * 1953-10-26 1960-06-14 Iwatsu Electric Co Ltd Multiplex telephone system
US2962553A (en) * 1954-11-23 1960-11-29 Donald E Campbell Coding and decoding system
US2920143A (en) * 1955-06-20 1960-01-05 Companhia Portuguesa Radio Mar Redundancy reducing pulse communications system
US2890285A (en) * 1955-10-25 1959-06-09 Bell Telephone Labor Inc Narrow band transmission of speech
BE557017A (en) * 1956-04-26
US3024311A (en) * 1957-01-29 1962-03-06 Ampex Signal system
US2938079A (en) * 1957-01-29 1960-05-24 James L Flanagan Spectrum segmentation system for the automatic extraction of formant frequencies from human speech
US3069506A (en) * 1957-09-04 1962-12-18 Ibm Consonant response in narrow band transmission
US3059054A (en) * 1958-04-28 1962-10-16 Paramount Pictures Corp Audio nonsense generator
AT251656B (en) * 1965-03-25 1967-01-10 Ibm Oesterreich Internationale Processes and arrangements for improving the speech quality in vocoder systems
US3499996A (en) * 1966-12-30 1970-03-10 Octronix Inc Bandwidth compressor and expander
GB8326719D0 (en) * 1983-10-06 1983-11-09 British Telecomm Digital coding

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2243527A (en) * 1940-03-16 1941-05-27 Bell Telephone Labor Inc Production of artificial speech
US2635146A (en) * 1949-12-15 1953-04-14 Bell Telephone Labor Inc Speech analyzing and synthesizing communication system
US2659823A (en) * 1951-09-21 1953-11-17 Jr Carl A Vossberg Measuring system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3247322A (en) * 1962-12-27 1966-04-19 Allentown Res And Dev Company Apparatus for automatic spoken phoneme identification
US4315105A (en) * 1976-11-23 1982-02-09 Miller Iii Herman P Narrow band transmission system and method

Also Published As

Publication number Publication date
US2810787A (en) 1957-10-22

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