Improving the kelly-lochbaum vocal tract model using conical tube sections and fractional delay filtering techniques
Vesa Välimäki, Matti Karjalainen · 1994
An articulatory model of speech production is usually constructed by approximating the profile of the vocal tract using cylindrical tube sections. This is implemented by a digital ladder filter that is called the Kelly--Lochbaum model. In this paper we propose an extended approach, where the tube sections approximating the profile of the tract are conical instead of cylindrical. Furthermore, the length of each tube section in our model can be accurately controlled using a novel fractional delay filtering scheme. These refinements result in an accurate and intuitively controllable vocal tract model that is well suited for articulatory speech synthesis. I. INTRODUCTION An articulatory model for the human vocal tract is traditionally constructed by approximating the profile of the vocal tract using cylindrical tube sections. The resulting tube system is then modeled by a digital ladder filter. This approach was first used in [1] and is called the Kelly-- Lochbaum (KL) model. There are tw...