Second, a new method is examined that uses a static-shaped rectangular mesh with the area function translated into an impedance map which is then applied to each waveguide. Two approaches for constructing such a map are demonstrated; one using a linear impedance increase to model a constriction to the tract and another using a raised cosine function. Recommendations are made towards the use of the cosine method as it allows for a wider central propagational channel. It is also shown that this impedance mapping approach allows for stable dynamic shape changes and also permits a reduction in sampling frequency leading to real-time interaction with the model.

eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. T he digital waveguide mesh (DWM) is a numerical simulation technique based on the definition of a regular spatial sampling grid for a particular problem domain, which in this specific case is a vibrating object capable of supporting acoustic wave propagation resulting in sound output. It is based on a simple and intuitive premise-the latter often considered important by the computer musicians who are the primary users of a sound synthesis algorithm-yet the emergent behavior is complex, natural, and capable of high-quality sound generation. Hence, the DWM has been applied in many areas of computer music research since it was first introduced by Van Duyne and Smith in 1993 [1]. This article is the first to attempt to consolidate and summarize this work. The interested reader is also directed to [2], where DWM modeling is considered in the more general context of discrete-time physics-based modeling for sound synthesis, and [3], where the DWM is examined within a rigorous theoretical and comparative framework for more established yet related wave scattering numerical simulation techniques. THE ONE-DIMENSIONAL DIGITAL WAVEGUIDEThe one-dimensional (1-D) digital waveguide is based on a time and space discretization of the d'Alembert solution to the 1-D wave equation. This approach to sound synthesis was first used in the Kelly-Lochbaum model of the human vocal tract for speech synthesis [4] and has parallels with other, more generally applied wave variable scattering modeling paradigms such as the transmission line matrix (TLM) method [5]

Abstract-Digital

The Digital Waveguide Mesh is a technique used in the modelling of room acoustics and musical instruments. This paper details a project that applies the theory of waveguide mesh acoustic modelling to the production of human-like vowel sounds. A 2D software mesh model is created that approximates the shape of the vocal tract in different vowel positions, and a glottal flow input is applied. The resulting signal bears similar resonant frequencies or formants to that of recorded speech. Recommendations are made towards extending the model to include some of the more complex features of the mouth, potentially constructing an acoustical model of the human vocal tract capable of creating speech sounds of increased naturalness.

No abstract