I took part in the EAA Winter School entitled “Cutting Edge in Spatial Audio”. It was a great workshop with great talkers and nice audio demonstrations.
Also the following DAGA conference was very interesting and a lot of fun. I presented my paper (see here) and met a lot of young acoustics people.
DAGA 2013 will take place in Meran, Italy. This is the abstract:
Array modes of compact rigid microphone arrays with unconventional shapes
Fabio Kaiser, Franz Zotter, Filippo Fazi
Compact, rigid spherical microphone arrays and their advantages are well-known. Their
signal processing employs a frequency-independent spherical harmonic decomposition of the microphone signals. A valid far field sound field description is obtained by individual
equalization of the resulting signals by filtering. Any subsequent beamforming achieves an
isotropic spatial resolution and is only a frequency-independent combination of signals. This is possible because the spherical harmonics are modes that separate the scattering problem imposed by the rigid sphere. An analytic separation of such modes for other, more complex array shapes (finite cylinder, finite cone, etc.) is not as easy to find. Nevertheless, these array shapes might be beneficial in applications that desire non-isotropic resolution. This work discusses the calculation of modes for rigid array shapes based on their scattering operator. This operator is numerically described by the boundary element method. Subsequent singular value decomposition of the scattered surface sound pressure due to all plane waves yields the modes and their strengths. The approach promises a similarly simple signal processing as employed with spherical arrays, after the quasi-continuous modes are used for array signal decomposition.
Internoise 2013 will take place in Innsbruck from September 15th-18th (http://www.internoise2013.com/). Here’s the abstract we submitted:
Orlando theme park acoustics – A soundscape analysis
Fabio Kaiser and Thorsten Rohde
Theme parks are self-contained environments creating a fantasy world with a very special purpose – entertaining. It is self-evident that sound plays a crucial role in the design of a visitor’s experience. In order to identify the relationship between a park’s architecture, the prevalent activities and the acoustics the soundscape approach is applied. It not only comprises quantitative measures but also perceptual and context-based measures and therefore seems to be most promising for the task. For this research four different theme parks in Orlando, USA, were evaluated during one day each. Soundwalks using binaural microphones as well as standard sound level measurements of single point-of-interest and the daily sound exposure were carried out. Further the sound quality and the context were captured by filling out evaluation forms. These methods helped in identifying characteristics, e.g., of noise sources of a contextual positive quality as well as sources having a rather negative effect. Examples of destructive acoustic design were identified and sound levels of attractions and of the daily exposure were measured that reach critical values. This work also discusses the use of the soundscape analysis for the consulting on the acoustic design of new theme parks.
I presented a paper entitled “Investigations on Cylindrical Microphone Arrays” written together with Hannes Pomberger and Franz Zotter from the IEM. Basically this work deals with the spatial resolution of a rigid cylindrical microphone array in different layouts. We propose a measure for the spatial resolution. Simulations of the array were done using the Boundary Element Mehtod (BEM).
The AES UK/Ambisonics Symposium 2012 took place in York, UK. A small but charming city. York is the home of Ambisonics pioneer Dave Malham. It was an exciting conference to be at!
This paper was part of my master thesis. More information on that see here.
F. Kaiser, H. Pomberger, and F. Zotter, “Investigations on cylindrical microphone arrays”, 4th International Symposium on Ambisonics and Spherical Acoustics, York, UK, March 2012. [pdf] [slides]