V.Yu.Semenov A novel approach to computation of the speech signal line spectral frequencies based on the interframe ordering property |
Acoustic bulletin, Vol. 7 ¹ 3, (2004) |
| The paper is dedicated to an important problem of calculation of line spectral frequencies (LSF), being the alternative form of representation of all-pole vocal tract model. Investigation of LSF relative position on the adjacent quasi-stationary time intervals (frames) is performed. On this basis a new two-stage approach to LSF calculation is proposed. This approach consists of two parts: LSF localization and their refinement. It was shown that the localization stage is effectively reduced to verification of interframe ordering property. It is also demonstrated how LSF values obtained in the previous frame can be used to accelerate the LSF refinement stage. As a result of testing on various speech signals, the 2.5 times reduction of the number of operations is shown in comparison with the similar algorithm without allowance for a priory information about relative LSF position on the adjacent frames. It was also shown that computational expenses are reduced 3.4 times in comparison with widely used Kabal's method. Moreover, it is demonstrated that the maximum (peak) computational expenses of the proposed method are lower than minimal ones both for Kabal's method and the accelerated combination of Kabal's method with Newton's method. These results show the advantage of applying the proposed method in real-time systems. |
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KEY WORDS: line spectral frequencies, all-pole vocal tract model, frame, Kabal's method |
| TEXT LANGUAGE: Russian |