Sound Technologies Lab

Showroom and Study Laboratory with Living Environment

Newly developed technologies are integrated in specific application scenarios in the study laboratory of the Oldenburg Branch for Hearing, Speech and Audio Technology HSA.

Communication Acoustics Simulator

© Hoertech gGmbH

With the unique Communication Acoustics Simulator the acoustics of nearly every listening room can be simulated. The acoustic parameters of this room – reverb time and acoustic room size – can be changed and virtual sound sources can be placed inside. This way, acoustic characteristics of office buildings, cathedrals, concert halls and even train stations and bathrooms can be simulated. The room can be used for research projects that require definite, variable acoustic room characteristics and specific background noise situations.

  • 93 m2
  • electronic acoustic VRAS (Variable Room Acoustic System) for generating different reverberation and early reflection patterns
    variably set reverberation time of approx. 0.4 s to 6 s
  • Audiosignal matrix (LCS) with special DSP hard- and software
  • 16 microphones fixed invisibly to the ceiling
  • 24 loudspeaker channels (12 for reverberation, 12 for early reflection)
  • Subwoofer for low-frequency extension and for dolby surround input in VRAS
  • 8 input channels for surround noise scenarios and dolby surround performances
  • Connectors and patch fields for temporary microphones and loudspeakers
  • Audiovisual media equipment
  • Induction system for the hearing impaired


Equipment for User Studies

  • Video lab with one-way window
  • Eye tracking recorders
  • Neurophysiological measurements of cognitive stress by electroencephalography (EEG)
    •    mobile, wireless 24-channel EEG
  • Neuropsychological test batteries for testing hearing capability, memory and executive functions
© Fraunhofer IDMT/Tobias Trapp
Evaluation Study
© Fraunhofer IDMT/Tobias Trapp
User-Centered Design
© Fraunhofer IDMT/Daniel Schmidt
EEG Study

Audiometric Booths

A total of nine acoustic measuring booths with a size of 3 to 29 m2 are available to the Institute for acoustic analysis. In addition to psychoacoustic fundamental research, the booths can also be used for measuring standard-audiometric parameters as well as complex free range setups and ERA/OAE devices.

© Fraunhofer IDMT
Audiometric Booth at the House of Hearing
© Hoertech gGmbH

Anechoic Room

Anechoic Room

Because of its size, equipment and frequency characteristic our anechoic room is ideally suited for precise acoustic measurements and psycho-acoustic tests. Additional Equipment is available for accurate sound-source localization experiments.

  • lower cut-off frequency 50 Hz
  • level of background noise lower than hearing threshold
  • spring supported absorber wedges (1.5 m long) to avoid frequency vibrations of 5 Hz and higher
  • Equipped for multi-channel playout and audio recording


Echo Chamber

Ausstattung Hallraum

This echo chamber has been built in 2005 at the Institute of Technical and Applied Physics GmbH (itap) at Oldenburg University. It is a standard size echo chamber that is used for research by Fraunhofer IDMT. In this chamber, acoustic features of materials and components are analyzed and the sound power is measured in machine acoustics.

  • 200 m2
  • Planning and calculation of acoustic conditions of rooms (DIN 18041) and buildings (DIN 4109)
  • Inspection and evaluation of airborne sound insulation of walls, ceilings and other components according to DIN EN ISO 140 and DIN EN ISO 717
  • Inspection and evaluation of impact sound insulation of ceilings according to DIN EN ISO 140 and DIN EN ISO 717
  • Measurement of room acoustic parameters
  • Measurement sound absorption of components and materials in echo chamber according to DIN EN ISO 354

Wind Tunnel

Fraunhofer IDMT uses the wind tunnel of the Oldenburg University to analyze influences of air flow on audio systems, e. g. on multimedia and communication devices worn at ones body.


  • Construction type: open measuring section, closed circuit; "Göttingen Type"
  • Speed: max. 50 m/s
  • Intensity of turbulence: under 0.3 %
  • Beam width: 1.0 m x 0.8 m
  • Drive: Radial fan with DC motor 77 kW
  • Flow measuring technology: 2D laser Doppler anemometer (LDA), hot wire anemometer, miniature-fan anemometer, acoustic turbulence probes, particle-image-velocimetry (PIV)
  • Acoustic measurement equipment: directional microphone array; in-flow measurements with flow microphones; correlation procedures for pseudo sound suppression