Pitch extractor apparatus and the like
US4627323A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 13, 1984 |
| Grant date | Dec 9, 1986 |
| Priority date | — |
| Expiry date | Aug 13, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H2210/066
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A method of (and apparatus for) extracting the fundamental pitch period of a complex electrical signal V.sub.2 (t), that includes the serial steps of deriving a time varying reference signal V.sub.ref (t) from the complex electrical signal V.sub.2 (t), which reference signal V.sub.ref (t) adapts continuously (i.e., each cycle of the complex electrical signal) to peak amplitude excursions of the complex electrical signal V.sub.2 (t); sensing ascending values of the signal V.sub.2 (t) to a first point at which the maximum magnitude of the signal V.sub.2 (t) of one polarity is reached and reversal of direction thereof occurs; storing the first substantially instantaneous difference in magnitude between the complex electrical signal V.sub.2 (t) and the time varying reference V.sub.ref (t) at the point of maximum magnitude of the signal V.sub.2 (t); thereafter sensing a point at which the magnitude of the signal V.sub.2 (t) minus the first substantially instantaneous difference equals zero; thereafter sensing ascending values of the signal V.sub.2 (t) to a further point at which a maximum magnitude of the signal V.sub.2 (t) of opposite polarity to the one polarity is reached and reversa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.