Duration modification using glottal closure instants and vowel onset points

Abstract

This paper proposes a method for duration (time scale) modification using Glottal Closure Instants (GCI, also known as instants of significant excitation) and Vowel Onset Points (VOP). In general, most of the time scale modification methods attempt to vary the duration of speech segments uniformly over all regions. But it is observed that consonant regions and transition regions between a consonant and the following vowel, and between two consonant regions do not vary appreciably with speaking rate. The proposed method implements the duration modification without changing the durations of the transition and consonant regions. Vowel onset points are used to identify the transition and consonant regions. A VOP is the instant at which the onset of the vowel takes place, which corresponds to the transition from a consonant to the following vowel in most cases. The VOPs are computed using the Hilbert envelope of Linear Prediction (LP) residual. The instants of significant excitation correspond to the instants of glottal closure (epochs) in the case of voiced speech, and to some random excitations, like the onset of burst, in the case of nonvoiced speech. Manipulation of duration is achieved by modifying the duration of the LP residual with the help of instants of significant excitation as pitch markers. The modified residual is used to excite the time-varying filter whose parameters are derived from the original speech signal. Perceptual quality of the synthesized speech is found to be natural. Performance of the proposed method is compared with the method, where the duration of speech is modified uniformly over all regions. Samples of speech signals for different modification factors is available for listening at

VOP Detection for Read and Conversation Speech using CWT Coefficients and Phone Boundaries

“…Mostly, VOP detection methods are studied for read mode of speech [6,8,10,[12][13][14]. However, speech can be broadly divided into two modes, such as read and conversation.…”

“…Therefore, the performance of the speech recognition system will be affected by the accuracy of the VOP detection method [4]. In literature [6,8,[10][11][12][13][14], traditional vowel onset point detection methods are developed for read mode of speech. However, in a realistic scenario, conversation speech is more frequently observed than the read speech [15,16].…”

An Efficient Synthesis and In vitro Cytostatic Activity of 5-Aminosulfonyl Uracil Derivatives

“…HE pyrimidine derivatives are known as essential constituents of nucleic acids and exhibit a variety of biological activities [1] notable among which are the antibacterial, [2][3][4] anticancer, [5][6][7][8] anti-inflammatory, [9,10] antitubercular, [11] analgesic, [12] and antiviral [13][14][15] activities. The pyrimidine base with modification at C5 position provides the enhanced biological activity of the nucleobase and nucleoside analogs.…”

Significance of glottal activity detection for duration modification

“…Duration modification is the process of modifying the speech rate according to desired modification factors without affecting the pitch, spectral and speaker characteristics of the original speech [1,2]. Duration modification of speech finds important applications in modifying the speech rate of slow or fast speech there by improving the intelligibility and naturalness [3].…”