Abstract: A method of estimating the pitch of a speech signal comprises the steps of sampling the speech signal to obtain a series of samples, dividing the series of samples into segments, each segment having a fixed number of consecutive samples, calculating for each segment a conformity function, and detecting peaks in the conformity function. The method provides also an intermediate signal derived from the speech signal, which is set to logical “1” where the intermediate signals exceeds a pre-selected threshold and to logical “0” where the intermediate signal does not exceed the pre-selected threshold, calculating the autocorrelation of the binary signal, and using the distance between peaks in the autocorrelation of the binary signal as an estimate of the pitch. Elaborate operations needed in prior art algorithms is thus avoided. A device conforming to the method is described.

Abstract: A method of estimating the pitch of a speech signal comprises the steps of dividing the speech signal into segments, calculating for each segment a conformity function, and detecting peaks in the conformity function. The method further comprises the steps of estimating an average distance between said peaks, and using the estimated average distance as an estimate of the pitch. In this way a method less complex than prior art methods, and thus suitable for small digital signal processors, is provided. The method also avoids the pitch halving situation. When the method is based on the fact that the identified peaks in the conformity function show a periodic behavior and that the true pitch period actually corresponds to the distance between the peaks, a simpler algorithm is achieved which provides the true pitch period independent on the occurrence of pitch halving, pitch doubling, etc. A similar device is also provided.

Abstract: A method of converting the speech rate of a speech signal with a pitch period below a maximum expected pitch period comprises the steps of dividing the speech signal into segments, estimating the pitch period in a segment, copying a fraction of the speech signal in the segment, said fraction having a duration equal to said estimated pitch period, providing from the fraction an intermediate signal having the same duration, and expanding the segment by inserting the intermediate signal pitch synchronously into the speech signal of the segment. A segment size longer than the maximum expected pitch period but shorter than twice the maximum expected pitch period is used. A considerably smaller amount of data has to be processed for each segment, so that the method can be implemented with the limited computational resources of e.g. a mobile telephone. A similar device is also provided.

Abstract: A method of converting the speech rate of a speech signal (2) with a pitch period below a maximum expected pitch period comprises the steps of dividing the speech signal into segments, estimating the pitch period in a segment, copying a fraction of the speech signal in the segment, said fraction having a duration equal to said estimated pitch period, providing from the fraction an intermediate signal having the same duration, and expanding the segment by inserting the intermediate signal pitch synchronously into the speech signal of the segment. A segment size longer than the maximum expected pitch period but shorter than twice the maximum expected pitch period is used. A considerably smaller amount of data has to be processed for each segment, so that the method can be implemented with the limited computational resources of e.g. a mobile telephone. A similar device is also provided.

Abstract: A method of estimating the pitch of a speech signal comprises the steps of sampling the speech signal to obtain a series of samples, dividing the series of samples into segments, each segment having a fixed number of consecutive samples, calculating for each segment a conformity function, and detecting peaks in the conformity function. The method provides also an intermediate signal derived from the speech signal, which is set to logical “1” where the intermediate signals exceeds a pre-selected threshold and to logical “0” where the intermediate signal does not exceed the pre-selected threshold, calculating the autocorrelation of the binary signal, and using the distance between peaks in the autocorrelation of the binary signal as an estimate of the pitch. Elaborate operations needed in prior art algorithms is thus avoided. A device conforming to the method is described.

Abstract: A method of estimating the pitch of a speech signal (2) comprises the steps of dividing the speech signal into segments, calculating for each segment a conformity function, and detecting peaks in the conformity function. The method further comprises the steps of estimating an average distance between said peaks, and using the estimated average distance as an estimate of the pitch. In this way a method less complex than prior art methods, and thus suitable for small digital signal procesors, is provided. The method also avoids the pitch halving situation. When the method is based on the fact that the identified peaks in the conformity function show a periodic behavious and that the true pitch period actually corresponds to the distance between the peaks, a simpler algorithm is achieved which provides the true pitch period independent on the occurrence of pitch halving, pitch doubling, etc. A similar device is also provided.

Abstract: A method of estimating the pitch of a speech signal (2) comprises the steps of dividing the signal into segments, calculating for each segment a conformity function, and detecting peaks in the conformity function. Further, an average of pitch estimates from previous segments is calculated; for each peak the difference between its position and the average is calculated; and the position of the peak having the smallest difference is used as an estimate of the pitch. In this way a method less complex than prior art methods, and thus suitable for small digital signal processors, is provided. The method also avoids the pitch halving situation. When previously detected pitch period estimates are available, a small difference is expected between the correct pitch period and the average of the previous pitch periods. A similar device is also provided.