US4809334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for detection and correction of errors in speech pitch period estimates
Assignee: Comsat Corp
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Filing: 1987-07-09
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Granted: 1989-02-28
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Expires: 2007-07-09
Abstract
Abstract A method of detecting and correcting received values of a pitch period estimate of a speech signal for use in a speech coder or the like. An average is calculated of the nonzero values of received pitch period estimate since the previous reset. If a current pitch period estimate is within a range of 0.75 to 1.25 times the average, it is assumed correct, while if not, a correction process is carried out. If correction is required successively for more than a preset number of times, which will most likely occur when the speaker changes, the average is discarded and a new average calculated.
Inventors
- 👤 Udaya Bhaskar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:54
CPC Classifications
G; G10; G10L; G10L25/00; G10L25/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
72 words
A method for detecting and correcting gross errors in pitch period estimates of a speech signal, comprising the steps of: determining an average of nonzero values of received pitch period estimates; accepting a current pitch period estimate if said current pitch period estimate is within a predetermined range of said average; and correcting said current pitch period estimate if said current pitch period estimate is outside said predetermined range of said average.
Claim 2
Independent Claim
72 words
A method for detecting and correcting gross errors in pitch period estimates of a speech signal, comprising the steps of: determining an average of nonzero values of received pitch period estimates; accepting a current pitch period estimate if said current pitch period estimate is within a predetermined range of said average; and correcting said current pitch period estimate if said current pitch period estimate is outside said predetermined range of said average.
Claim 3
Dependent Claim
27 words
The detecting and correcting method of claim 1, wherein said predetermined range is 0.75P(i)<p(i)<1.25P(i), where P(i) is said average and p(i) is said current pitch period estimate.
Claim 4
Dependent Claim
65 words
The detecting and correcting method of claim 1, wherein said step of correcting said current pitch period estimate comprises: (1) if preceding and succeeding pitch period estimates p(i-1) and p(i+1), respectively, are both nonzero, setting p(i) equal to an average of p(i-1) and p(i+1); and (2) if one of p(i-1) and p(i+1) is nonzero, setting p(i) equal to the nonzero one of p(i-1) and p(i+1).
Claim 5
Dependent Claim
25 words
The detecting and correcting method of claim 3, further comprising the step of, if both p(i-1) and p(i+1) are zero, setting p(i) equal to zero.
Claim 6
Dependent Claim
58 words
The detecting and correcting method of claim 4, further comprising the steps of: counting a number of consecutive times of correcting said current pitch period estimate p(i) without p(i) being in said predetermined range or p(i) being set equal to zero; and discarding said average and determining a new average when the count exceeds a predetermined limit value.
Claim 7
Dependent Claim
15 words
The detecting and correcting method of claim 4, wherein said predetermined limit value is three.
Claim 8
Dependent Claim
34 words
The detecting and correcting method of claim 1, wherein said step of determining said average comprises recursively calculating: ##EQU3## where N nz is a number of nonzero values of p(i) included in said average.
Claim 9
Dependent Claim
40 words
The detecting and correcting method of claim 1, wherein said step of averaging comprises averaging a predetermined minimum number of nonzero values of said received pitch period estimate before proceeding to said step of accepting a current pitch period estimate.
Claim 10
Dependent Claim
15 words
The detecting and correcting method of claim 8, wherein said predetermined minimum number is eight.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-28 | 1992-08-29 | 1993-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-28 | 1996-08-29 | 1997-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-28 | 2000-08-29 | 2001-02-28 | $7700.00 | Window Closed / Lapsed |