An Improved Digital Waveguide Model of a Flute with Fractional Delay Filters
Rami Hänninen, Vesa Välimäki · 1996
this paper we concentrate on digital waveguide synthesis of the flute, which has been a target of active research during the recent years. The first version of a real-time digital waveguide flute model was introduced by Karjalainen et al. [2] and Välimäki et al. [3]. Cook has implemented a simplified version of this model [4]. Similar principles for simulating the air reed mechanism of the flute had been used by McIntyre et al. [5] and Wawrzynek [6]. More recently also Coltman [7] has reported on a flute simulation model. Newest developments in flute modeling include the works of Chafe [8] and Cook [9]. A more detailed and physically accurate flute model could be constructed based on recent research by Verge [10]. Other research work on flute synthesis using a time-domain model include [11], [12], and [13]. This paper introduces an improved digital waveguide model of a flute which features a full set of finger holes. The model responds correctly to real playing techniques, including the fingering combinations, overblowing and vibrato. Many of the flute model parameters, such as the lengths of delay lines and finger hole filter parameters, have been computed from measurements taken from a real flute. Rami Hänninen AN IMPROVED DIGITAL WAVEGUIDE MODEL OF A FLUTE So far, many implementations have failed to produce realistic flute sound that could be controlled using the same techniques that are used to play a real flute. One of the major problems has been the note transition. Changing the length of the delay lines of the waveguide flute changes the pitch but produces an audible `click' when the internal state of the model abruptly changes. On the other hand, changing the length of the delay lines gradually changes the state smoothly but produces an undesirable pitch-bend ...