Masterproeven 2012-2013

Design and validation of a middle ear simulator


The ear drum and middle ear ossicles transfer sound waves coming into the ear canal into vibrations. A middle ear microphone is a sensor which is coupled to one of the ossicles of the middle ear to convert these vibrations, and thus sound, into an electrical signal. Such an electrical signal can be used as input for a future generation of fully implantable cochlear implants (Figure 1).

Figure 1 A cochlear implant with middle ear microphone attached to the anvil

In CTC a model of the middle ear transfer function and middle ear microphone was developed. Moreover, prototypes were built and tested in cadaver heads. However, up to date no standard reliable bench test for this type of microphones is available.


The goal of this project is to develop, build and validate a middle ear simulator. This device should be able to generate vibrations similar to those of the middle ear ossicles. In the in vivo situation, by coupling a middle ear microphone to the ossicles, the mobility of these ossicles will be inherently affected. The device should be able to mimic these effects accurately. Figure 2 shows a schematic overview of a middle ear simulator.

Figure 2 Schematic overview of middle ear simulator

Required skills/interests: This project consists of several steps:

  1. Design of middle ear simulator based on available model and experimental data (50%). Skills/interests: Matlab, CAD, theoretical mechanics and/or electronics
  2. Build prototype (30%). Skills/interests: hands-on mechanics and/or electronics
  3. Validate prototype (20%). Skills/interests: Matlab, cadaver experiments

During this project, a strong interaction with the engineers at CTC is essential.

Student: Kasper Malfroid
Promotoren: Prof. Benedict Verhegghe, Prof. Pieter Rombouts
Scriptiebegeleider: Joris Walraevens [Cochlear]