An attempt to use an electrical circuit simulator to better understand the relationship between a brass player

Understanding the mechanism of sound production is essential to predict intonation, response and sound of brass instruments. According to Ayers (visualising lip surface waves), Campbell (artificial lips), Adachi et.al. (physical modelling), tone generation on brass wind instruments cannot be satisfactory described by models ignoring lips as independent vibratory systems exhibiting wave propagation and being subject to sound pressure, Bernoulli force and even other forces. Transmission line modelling could be a way to model the distributed nature of lips and wave propagation in and on them. Simulation of such feedback loops including non-linear lip valves using the circuit simulator SPICE is presented. INTRODUCTION Understanding all essentials about the oscillator of wind instruments is keeping musical acousticians from all over the world busy up to now. Helmholtz [1] classified wood wind instruments as having reeds operating like inward striking doors tending to close with increased mouth pressure. This classification is obvious and has not been questioned in the past. On the other side, his classification of brass wind instruments as having lip reeds operating like outward striking doors, opening with the blowing pressure, has triggered ongoing discussions and arguments. Much later in 1982 Elliot and Bowsher [2] raised the question about the role of the time-varying Bernoulli pressure, which has the ability to close the valve by applying a force perpendicular to the direction of air flow. This idea was elaborated by Saneyoshi et al. [3] introducing a third concept, which is now referred to as transverse model. The three concepts are illustrated in Figure 1, which was taken from publications of Adachi [4][5], where a much deeper investigation of these models can be found.