Inverse acoustics (TWO.6618)

Noise problems have been around for a long time. Because nowadays the tendency is towards lightweight and low-cost design, noise problems arise more frequently. Efficient countermeasures to reduce noise can only be taken if one knows how it is generated. Unfortunately, in many cases the exact location of the sound source is unknown. In such situations inverse acoustics is a very attractive method to determine the location and the strength of sound sources. This method has some resemblance with an "acoustic camera", which visualizes the sound sources of a sound-emitting device. The key feature is that the input (i.e. the vibrating structure that radiates sound) is reconstructed from the measured data (i.e. the measured sound quantities). This reconstruction requires an inversion, which is reflected in the name of the project; "inverse acoustics".
Current methods for source localization are seriously hampered by the fact that they are costly with respect to hardware and computational effort and - even more important - they can only be applied to a limited class of problems. Moreover, closely spaced sources, as frequently encountered in practice, cannot be distinguished.
To overcome these shortcomings a new project is proposed in which along three, closely coordinated lines of improvement are sought:
(1) improved numerical modeling and validation,
(2) improved measurement techniques and signal processing,
(3) fast and user-friendly data acquisition and data reduction methods.

In industry there is a clear need for a new generation of measurement techniques for source localization. Various companies have expressed their interested in the proposed project and are potential users of the source localization equipment and associated methods.