(19)
(11) EP 0 440 335 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.04.1992 Bulletin 1992/18

(43) Date of publication A2:
07.08.1991 Bulletin 1991/32

(21) Application number: 91300106.1

(22) Date of filing: 08.01.1991
(51) International Patent Classification (IPC)5: G10L 9/14
(84) Designated Contracting States:
AT BE DE ES FR GB IT NL SE

(30) Priority: 01.02.1990 GB 9002282

(71) Applicant: PSION PLC
London, NW8 8NQ (GB)

(72) Inventor:
  • Wolovitz, Lionel Berel
    London E3 5DB (GB)

(74) Representative: Wells, David et al
British Telecommunications plc, Group Legal Services, Intellectual Property Department, 8th Floor, Holborn Centre, 120 Holborn
London EC1N 2TE
London EC1N 2TE (GB)


(56) References cited: : 
   
       


    (54) Encoding speech


    (57) An apparatus for encoding speech includes circuits (2,9) which sample a speech signal and generate digital data representative of the signal. An encoder (10,11) connected to the sampling circuits encodes the digital data by linear predictive coding and generates parameters representing the speech signal. The parameters are transformed (12) to obtain sum and difference polynomials. The roots of the sum and difference polynomials are determined (13) producing a series of line spectrum data. A storage device (14,15) stores the line spectrum data.
    In one example, the line spectrum data are quantised non-uniformly in the frequency domain and the roots of the polynomials are found by evaluating those polynomials at the quantisation frequencies only.






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