Supervision: Hervé Lissek

Project type: Semester project (master) Master thesis

Available

A wind instrument can generally be assimilated to a axisymmetric hollow duct, with varying (or constant) cross-section along the main axis. One extremity of the duct may be open or closed (the mouth, that can be a reed - see a saxophone -, a mouthpiece - see a trombone - or an open hole - see the flute), whereas the other end (the bell) is generally horn-shaped.

It is well known that the timbre of the instrument is associated with the shape of the bell, the type of flow excitation by the lips at the mouthpiece, and, more importantly, to the boundary conditions at the two extremities (open/open, closed/open): this specifies the nature of resonances inside the main duct, which yields a certain series of resonance frequencies (harmonics).

Then, it is noticeable that the wind families (brass, wood, etc.) are not referring to the material in which it is made, but rather on the way sound resonates inside the instrument, and a woodwind instrument might be made of brass (see the saxophone for example).

A way to alter the timbre of a cylindrical duct would be to change the acoustic impedance at the bell. For that, the concept of Electroacoustic Resonator, developped in the lab, is likely to allow real-time modification of acoustic impedance at a certain position along the duct.

This project aims at developing a scaled prototype of an active wind instrument, made of an archetypal cylindrical hollow duct with straight terminations, around which a ring of active electroacoustic absorbers will be designed to control the acoustic impedance and alter the timbre of the duct. The work will consist in:

  • perform FEM simulations of the proposed design and identify potential control settings
  • develop an experimental prototype of wind-instrument "scale model"
  • perform acoustic assessment of the electroacoustic resonators as well as of the whole "wind instrument"

Profile

  • Electrical Engineering
  • Mechanical Engineering
  • Microengineering, Physics

Requirements

  • Electroacoustique
  • Audio engineering lectures

Learning outcomes

  • Acoustic instrumentation
  • COMSOL multiphysics
  • Speedgoat programming (Matlab/Simulink)

Content

  • COMSOL simulation (50%),
  • design, including control (25%)
  • acoustic assessment (25%)