Final Thesis

Measurement of Structure-Borne Sound Excitation by Headphones

Key Info

Basic Information

Research Area:
Acoustic Measuring Techniques,
Type of Thesis:


Bachelor Thesis of Ibe

Bone conduction has a big impact on the perception of the human being. Even though headphones are used by a billion of people around the world, it was yet not analyzed if the headphones excite structure-borne sound. Structure-borne sound they could cause bone conduction or cartilage conduction and interfere with the perception of the user. This thesis aims to take first steps in the characterization of the stimulated vibrations of headphones. An Laser Doppler vibrometry is used to measure the velocity on a headphone attached to an artificial ear on an acoustic test fixture. Additionally, the acoustic test fixture is also used to measure the sound pressure level. The laser is targeted on the headphones from different directions and angles, to get a three-dimensional impression of the motion. By measuring the sound pressure and the velocity of the headphone parallelly, the stimulated vibration is getting analyzed in a three-dimensional and in an energetic point of view. Based on the measurement results, the excitation and the vibration’s dependence on the boundary conditions will be discussed.