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Low-complexity method for improving the performance of autocorrelation-based pitch detectors

  • US 5,127,053 A
  • Filed: 12/24/1990
  • Issued: 06/30/1992
  • Est. Priority Date: 12/24/1990
  • Status: Expired due to Fees
First Claim
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1. A method of operating an autocorrelation pitch detector for use in a vocoder comprising the steps of:

  • tracking times of occurrence of a highest and a second-highest autocorrelation peak in an input signal;

    comparing amplitudes of said highest and second-highest autocorrelation peaks;

    identifying said times of occurrence to determine if the time position of said highest autocorrelation peak and the time position of said second-highest autocorrelation peak are in a predetermined ratio when said highest and second-highest autocorrelation peaks are within a predetermined percentage difference in amplitude; and

    selecting as a true autocorrelation peak one of said highest or second-highest autocorrelation peaks when said predetermined ratio exists between said time position of said highest autocorrelation peak and said time position of said second-highest autocorrelation peak.

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