Dietmar Jackel

University of Rostock

Speech synthesisArticulatory synthesisSpeech recognitionComputer scienceVocal tract

6Publications

4H-index

150Citations

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Publications 6

Newest

#1Peter Birkholz (University of Rostock)H-Index: 12

#2Dietmar Jackel (University of Rostock)H-Index: 4

Last. Bernd J. KrögerH-Index: 15

view all 3 authors...

Flow separation in the vocal system at the outlet of a constriction causes turbulence and a fluid dynamic pressure loss. In articulatory synthesizers, the pressure drop associated with such a loss is usually assumed to be concentrated at one specific position near the constriction and is represented by a lumped nonlinear resistance to the flow. This paper highlights discontinuity problems of this simplified loss treatment when the constriction location changes during dynamic articulation. The di...

#1Peter Birkholz (University of Rostock)H-Index: 12

#2Dietmar Jackel (University of Rostock)H-Index: 4

Last. Bernd J. KrögerH-Index: 15

view all 3 authors...

We present a novel 3D vocal tract model and a method to control the articulatory movements of the model. The vocal tract model consists of 7 wireframe meshes that represent the three dimensional surfaces of the articulators and the vocal tract walls. 23 parameters determine the shape of the meshes. The articulatory movements in terms of the parameter curves are generated from a gestural description of an utterance. The work presented here is an integral part of a complete articulatory speech syn...

#1Peter Birkholz (University of Rostock)H-Index: 12

#2Dietmar Jackel (University of Rostock)H-Index: 4

This paper describes how the boundary layer resistance can be considered in time domain simulations of the vocal tract system. The magnitude of the resistance is proportional to the square root of the frequency and is therefore difficult to include in traditional one-dimensional time domain simulations. We propose a method how the resistance can be included in such models based on a discrete representation of the velocity profile in the boundary layer. The boundary layer resistance can be consid...

Influence of temporal discretization schemes on formant frequencies and bandwidths in time domain simulations of the vocal tract system.

#1Peter Birkholz (University of Rostock)H-Index: 12

#2Dietmar Jackel (University of Rostock)H-Index: 4

A time domain simulation of acoustic propagation in the vocal tract requires the spatial and temporal discretization of the equations of motion and continuity. In the classic transmission line model of the vocal tract with lumped elements, the spatial discretization is provided by the piece-wise constant area function. The temporal finitedifference approximation of the differential equations can, however, vary from one implementation to the other (e.g., [4] vs. [5]). In this study, we have adopt...

#1Hermann Birkholz (University of Rostock)H-Index: 3

#2Dietmar Jackel (University of Rostock)H-Index: 4

To deform graphical objects, warping methods are often used, that allow precise control of the deformation. An efficient warping technique, based on feature vectors, was introduced by T. Beier and S. Neely [Beier T. 1992], that had successfully been proven oneself in the past. Hereby, the user is able to describe the geometry of source and destination object with pairs of vectors very precisely. In this work we present an extension of this method, by feature curves, that can be used in an arbitr...

#1Peter Birkholz (University of Rostock)H-Index: 12

#2Dietmar Jackel (University of Rostock)H-Index: 4

A three-dimensional model of the vocal tract is presented. The vocal tract walls and the tongue are represented by three individual grids. The shape of the grids is determined by a set of parameters specifying the form and position of the tongue, the lips, the velum, the larynx and the jaw. Both articulatory speech synthesis and the visualization of speech production can benefit from this three-dimensional representation of the vocal tract.

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