Different projects require different tools.

At ARI we design tools especially for particular projects to obtain optimal solutions. For instance we adapted the software framework ExpSuite, which is used for most of our psychoacoustic experiments, to our needs, and for the measurement of the head related transfer functions (HRTF) we designed loudspeakers which meet the acoustic requirements. We also developed a fast system identification method, the multiple exponential sweep method (MESM): this is a method for the fast and convenient measurement of HRTFs. In this section we present some tools from our lab.

The ARI lab consists of five testing and measurement stations:

  • GREEN and BLUE (ISF Grün, ISF Blau): Two sound-booths (IAC-1202A) are used for audio recording and psychoacoustic testing performed with headphones. Each of the booths is controlled from outside by a computer. Two bidirectional audio channels with sampling rates up to 192 kHz are available. The GREEN chamber is further equipped with a 64-channel EEG system (actiCHamp, Brain Products).
  • RED (ISF Rot): A visually-separated corner can be used for experiments with cochlear implant listeners. A computer controls the experimental procedure using a bilateral, direct-electric stimulation.
  • YELLOW (ISF Gelb): A Semi-Anechoic Room, with a size of 6 x 6 x 3 m, can be used for acoustic tests and measurements in a nearly-free field. As many as 24 bidirectional audio channels, virtual environments generated by a head mounted display, and audio and video surveillance are available for projects like HRTF measurement, localization tests or acoustic holography.
  • PURPLE (ISF Lila): A semi-anechoic loudspeaker array studio with 91 loudspeakers and 2 subwoofers on a size of 3 x 3 m. The system can be controlled from outside in the control room, using a multichannel audio setup with 4 amplifiers and a computer.

The rooms are not only used for measurements and experiments, but also for speech recordings, speaker identification and survey reports.

During the breaks in experiments, the subjects can use an internet terminal or relax on a couch in the lounge while sipping hot coffee...



The work at the ARI is largely done in the framework of projects. Projects may be internally or externally funded. They may be inter-discerplinery and international. Here you will find information about our current and completed projects.

Psychoacoustics concerns itself with the relationship between the acoustic signals and their subjective percept. Loudness, pitch and timbre are approximately the correlates of signal amplitude, frequency and frequency spectrum, respectively. Experimental and mathematical models describe the interrelations between the basis functions of auditory perception. Computational Auditory Scene Analysis (CASA) is an integrative approach to combine different fields of psychoacoustics. The results enter the research in sound localisation, speech and music perception, noise abatement etc.  

How to find us


Past Events

Past news

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The Acoustics Research Institute is involved in the creation and maintenance of a number of software packages used for acoustic research.

STx Documentation

This Section provides information on how to use STx:

to be contnued


Miscellaneous STx Scripts

STx Toolbox Functions Category - Export

a test category created by jw