GB1093102A - Improvements relating to methods and apparatus for reducing random variations in periodicity in a pulse signal - Google Patents
Improvements relating to methods and apparatus for reducing random variations in periodicity in a pulse signalInfo
- Publication number
- GB1093102A GB1093102A GB1316665A GB1316665A GB1093102A GB 1093102 A GB1093102 A GB 1093102A GB 1316665 A GB1316665 A GB 1316665A GB 1316665 A GB1316665 A GB 1316665A GB 1093102 A GB1093102 A GB 1093102A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pulse
- speech
- spacing
- pulses
- time interval
- 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
Links
- 238000000034 method Methods 0.000 title abstract 2
- 230000005284 excitation Effects 0.000 abstract 7
- 230000015556 catabolic process Effects 0.000 abstract 1
- 238000006731 degradation reaction Methods 0.000 abstract 1
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; 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
- G10L25/90—Pitch determination of speech signals
Landscapes
- Engineering & Computer Science (AREA)
- Computational Linguistics (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Audiology, Speech & Language Pathology (AREA)
- Human Computer Interaction (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Compression, Expansion, Code Conversion, And Decoders (AREA)
- Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
Abstract
1,093,102. Vocoder excitation function generator; pulse modulation systems. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 29, 1965 [April 6, 1964], No. 13166/65. Headings H4L and H4R. In a vocoder the excitation function, which is a series of pulses corresponding to unidirectional zero crossings of the fundamental frequency of the speech, is treated to reduce the effect of noise on the speech by deriving from the pulse train the mean value of the pulse spacing over a predetermined time interval and transmitting a pulse at this pulse spacing. The process is repeated for successive time intervals, each time interval commencing at a time after the commencement of the preceding time interval which is equal to the pulse spacing derived during the preceding time interval. The mean pulse spacing may be obtained by weighting each pulse spacing in the incoming signal in accordance with the time of occurrence of the pulse after the commencement of the interval, adding the weighted pulse spacings, and dividing the sum by a suitable factor. The Figure shows an excitation function generator for a vocoder in which the incoming speech is applied via a non-linear circuit NLG and a filter BP to a zero crossing detector ND and a pulse shaper IF to produce a pulse at every zero crossing in one direction of the fundamental frequency of the speech. The speech is also applied to a voiced-unvoiced detector D the output of which operates gates T1 and T2 so that during unvoiced sounds, when the excitation pulses are randomly spaced, the excitation pulses are fed direct to the output ANK<SP>1</SP> while during voiced sounds the pulses are fed to the units 1 to IV in order to derive the mean pulse spacings in accordance with the invention. The unit I comprises a device which measures the spacing between each pair of excitation pulses and stores these measured pulse spacings. The unit II then sums these pulse spacings over a measured interval, weighted in accordance with the time of occurrence after the start of the time interval if required, and divides them by the number of pulses, or some function thereof, to obtain the mean pulse spacing which is used in unit IV to generate the output excitation function pulse train. It is stated that the arrangement introduces some degradation into speech signals but may be advantageous under noisy conditions.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEJ25601A DE1200884B (en) | 1964-04-06 | 1964-04-06 | Method for smoothing the fundamental information in pulse-excited channel vocoder systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1093102A true GB1093102A (en) | 1967-11-29 |
Family
ID=7202297
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1316665A Expired GB1093102A (en) | 1964-04-06 | 1965-03-29 | Improvements relating to methods and apparatus for reducing random variations in periodicity in a pulse signal |
Country Status (5)
Country | Link |
---|---|
AT (1) | AT269950B (en) |
DE (1) | DE1200884B (en) |
FR (1) | FR1509916A (en) |
GB (1) | GB1093102A (en) |
SE (1) | SE316807B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4511917A (en) * | 1981-10-20 | 1985-04-16 | Hans Olof Kohler | Determining agreement between an analysis signal and at least one reference signal |
-
1964
- 1964-04-06 DE DEJ25601A patent/DE1200884B/en active Pending
- 1964-08-26 AT AT739264A patent/AT269950B/en active
-
1965
- 1965-03-29 GB GB1316665A patent/GB1093102A/en not_active Expired
- 1965-04-05 FR FR11899A patent/FR1509916A/en not_active Expired
- 1965-04-06 SE SE444465A patent/SE316807B/xx unknown
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4511917A (en) * | 1981-10-20 | 1985-04-16 | Hans Olof Kohler | Determining agreement between an analysis signal and at least one reference signal |
Also Published As
Publication number | Publication date |
---|---|
FR1509916A (en) | 1968-01-19 |
SE316807B (en) | 1969-11-03 |
DE1200884B (en) | 1965-09-16 |
AT269950B (en) | 1969-04-10 |
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