A new method for determining the instants of significant excitation in speech signals is proposed. Here, significant excitation refers primarily to the instant of glottal closure within a pitch period in voiced speech. The method is based on the global phase characteristics of minimum phase signals. The average slope of the unwrapped phase of the short-time Fourier transform of linear predictio...

ASTRONOMY AND ASTROPHYSICS High precision difference astrometry applied to the triplet of S5 radio sources B1803+784/Q1928+738/B2007+777 Abstract. We determined the separations of the radio sources in the triangle formed by the BL Lac objects 1803+784 and 2007+777, and the QSO 1928+738 from in-tercontinental interferometric observations carried out in November 1991 at the frequencies of 2.3 and...

In this paper, we propose a method for robust detection of the vowel onset points (VOPs) from noisy speech. The proposed VOP detection method exploits the spectral energy at formant frequencies of the speech segments present in glottal closure region. In this work, formants are extracted by using group delay function, and glottal closure instants are extracted by using zero frequency filter bas...

One of the key issues in practical speech recognition is to achieve robust gender identification. Most conventional gender identification approaches use relevant features derived from the magnitude spectrum. In this paper, we propose a novel gender identification method using a group delay function (GDF). Based on the statistical analysis of the GDF, it is found that the GDF is an effective fea...

This paper demonstrates the robustness of group-delay based features for speech processing. An analysis of group delay functions is presented which show that these features retain formant structure even in noise. Furthermore, a speaker verification task performed on the NIST 2003 database show lesser error rates, when compared with the traditional MFCC features. We also mention about using feat...

The effect of delay and reflectivity ripples of dispersion compensating fibre gratings on systems operated at 10 Gb/s over 100 km of standard single-mode fibre is investigated for partial or total dispersion compensation .

In this paper, we investigate a new method for extracting useful information from the group delay spectrum of speech. The group delay spectrum is often poorly behaved and noisy. In the literature, various methods have been proposed to address this problem. However, to make the group delay a more tractable function, these methods have typically relied upon some modification of the underlying spe...

A method for performing waveform invariant time stretching and pitch shifting on a quasi harmonic and sinusoidally modeled sound is presented. The method is based on the relative phase delay representation of the phase, defined as the difference between the phase delay of the partials and the phase delay of the fundamental. This representation makes the waveform characterization independent fro...

The magnetostrictive guided wave sensor with a single induced winding cannot distinguish axially symmetric from non-axially symmetric features in a pipe, because it is impossible for the sensor to detect the non-axially symmetric mode waves. When we study the effect of the change of the magnetic field in the air zone for receiving the longitudinal guided wave mode, we find that the change of th...

We study ultrabroadband slow light in a warm rubidium vapor cell. By working between the D1 and D2 transitions, we find a several-nanometer window centered at 788:4 nm in which the group index is highly uniform and the absorption is small (<1%). We demonstrate that we can control the group delay by varying the temperature of the cell, and we observe a tunable fractional delay of 18 for pulses a...