(1) Computational Acoustics deals with the simulation of structure and fluid dynamics, sound field modeling, and associated signal processing tasks. Tasks performed in this field include simulation, mathematical calculation, signal analysis, re-synthesis, and dedicated software development. Research in human and animal auditory perception requires profound knowledge of the physical structures of sound sources and sound fields over a wide range of frequencies. The picture compares the result of a classical Boundary Element Method (BEM) with the Multilevel Fast Multipole Method (MLFMM). The Fast Multipole Method considerably reduces the computational effort without a loss of accuracy.

In the field of (2) Psychoacoustics acoustic measurements, numerical simulations, and Psycho-Physiological Models are applied to specify and explain the function of hearing. The effect of acoustic signals is complex, encompassing daily speech and music listening, environmental noise, motor vehicle acoustics, and audio engineering. One of the main auditory functions concerns masking. The institute's own software package, STx, provides the modeling of simultaneous masking on natural sounds. This masking separates audible spectral components from inaudible ones by computing the so-called "irrelevance threshold."

The Acoustic Model of Speech Production provides the basis of analyzing speech sounds. (3) Acoustic Phonetics, in combination with Phonology, enables the study of articulatory and phonological differences between languages and speakers. Speech parameters, such as fundamental frequency contours, formant frequency tracking, and timing measures support the generation of phoneme and vowel systems as well as relevant linguistic speech sound classifications.

(4) Experimental Audiology and Psychoacoustics: We investigate the link between acoustic signals and auditory perception. This includes loudness and pitch perceptions, speech perception in noise, time-frequency masking, sound localization, spectral profiling, and auditory scene analysis. We study the auditory perception in acoustic hearing (both normal-hearing and hearing-impaired listeners) and electric hearing (cochlear-implant listeners) focusing on spatial hearing.

(5) Mathematics and Signal Processing in Acoustics focuses on application-oriented mathematics. It develops theoretical results and new mathematical concepts, motivated by application, in contrast to "applied mathematics" focusing on providing and applying mathematical tools for the applied sciences. The application-oriented approach allows results significant both for mathematics and the applied sciences. In this context we develop new mathematical concepts motivated by signal processing and acoustical applications.

The areas of basic and applied research are highly complementary. Many of the different approaches within the two research fields use similar methods. For example, they apply almost the same algorithms of time-frequency representation, digital filters, signal parameter, feature extraction, and common mathematics (Digital Signal Processing and Software Development –S_TOOLS-STx, Mathematics). The framework implemented utilizes the synergistic effects in theoretical and applied fields with the aim to handle the complex interaction between acoustics and auditory perception.