Even in the digital age, acoustics play an important role in sound transmission. The quality of a digital audio signal is significantly influenced by the acoustical conditions under which it is recorded and played back.

Room and building acoustics

In order to achieve optimum functionality and thus the greatest possible economy of a broadcast production room, acoustic properties must be precisely matched to the activities performed in it. Acoustic weak points are to be avoided as well as exaggeratedly complex constructions.

When developing solutions for studio acoustics and advising broadcasters as well as private clients on building projects, IRT attaches particular importance to the fact that all concepts and designs are precisely coordinated and fit together. Years of experience in the use of powerful calculation and simulation software as well as the highest professional competence in the field of acoustically high-quality sound and image production rooms (DIN 15996), but also in general questions of sound insulation in building construction (DIN 4109), are of great importance. The range of services is rounded off by needs-based measurements with high-quality measurement equipment in the areas of room and building acoustics and audio measurement technology in the company's own measurement rooms (reverberation room, anechoic chamber, etc.).

In addition, IRT manages the Acoustics Information Ring of the public broadcaster, develops the acoustic requirements in the field of broadcasting and makes recommendations. Furthermore, it maintains close contacts to the VDE ITG technical committees and DEGA-Fachausschuss.

Acoustics in open-plan offices

Large window areas and smooth wall surfaces often lead to a long reverberation time, which increases the noise level in a crowded room. This makes conversations and concentrated work more difficult and severely impairs employee performance, as studies have shown. On the other hand, it should be noted that good speech intelligibility in acoustically attenuated open-plan offices leads to a loss of privacy.

IRT advises on the acoustic design of open-plan and multi-person offices. In order to make the effect of typical measures audible, the "auralization of offices" can be used. In these extensive simulations, the subjective, audible level of perception is linked with technical parameters from evaluation standards, design guidelines and technical rules.

Acoustics in OB vans

High-quality outdoor productions in OB vans require that the technical conditions allow optimum working conditions. Therefore, adequate acoustics need to be provided as a workplace for sound engineers.

IRT supports radio and television broadcasters as well as private clients in the tendering of OB vans with regard to their acoustic properties. It carries out acoustic consultations to achieve the agreed values (e.g. interior level, sound insulation) and acoustic measurements for the acceptance of the OB vans.

Acoustic measurement technology

In the field of acoustic measurement technology, IRT carries out measurements of absorption and reflection coefficients, flow resistances, noise emissions, reverberation behaviour and structure-borne noise, sound insulation of a wide variety of components or acoustic data of electroacoustic transducers.

Measurement of directional characteristics of loudspeakers and microphones

In addition, IRT determines the directional characteristics of loudspeakers and microphones using a special computer-aided measuring apparatus. The measurement results are displayed in the form of specific transmission dimensions, various bundling dimensions, heat maps or as polar diagrams in selectable frequency resolution.

AUVIS - Room acoustic simulation

The professional room acoustic simulation software AUVIS (AUralisierung VIrtueller Studios) developed at IRT is used for the exact calculation of acoustic properties of broadcast production rooms. In addition to the reverberation time, other important acoustic parameters can be calculated and optimized in advance. For example, the transmission rate of the planned control room loudspeakers at the planned listening location of a control room can be determined. If the result does not meet the specifications within a tolerance range, the transmission factor can be optimized in the model by specific measures (e.g. variation of the loudspeaker position, room geometry or wall and ceiling absorption).

In addition, the impulse responses of different listening locations can be calculated in the model. This makes the simulated room "audible". Thus, it is already possible to hear how a certain recording will sound in the planned room before it has even been built, based on the calculation model. This procedure is called "auralization".

In practical application, room acoustic simulation has already proven its efficiency. The initial additional expenditure in the planning phase means that only structural measures are implemented that are necessary to fulfil the acoustic specifications.

The following sound examples were calculated and auralized with IRT's own simulation program AUVIS. The sound samples are only suitable for headphone reproduction.


As an expert system, AUVIS is used exclusively within the framework of the services offered by IRT and is not offered as a product.

Auralization of offices

In cooperation with the Federal Institute for Occupational Safety and Health (BAuA), IRT has developed auralizations for the planning of office spaces that can be displayed on any standard PC with an up-to-date Internet browser (HTML5-capable). The audio should be reproduced via headphones in order to experience the subjective effect of the measures presented in the best possible way with one's own senses. So, the necessity of a conscious acoustic organization and specialized planning of the work place environment can be simulated particularly to architects, civil engineers and owners as well as planners and operators of office space/work places.

The utilized player can be used to switch back and forth between the audio examples without gaps in order to compare the audio examples directly with each other and to perceive the differences best. The variants are documented on floor plans. For open-plan offices, attractive 3D visualizations are also available to illustrate the visual effect of the measures presented from the user's perspective.

Software instruction

Acoustic services at a glance

  • Expert advice in room and building acoustics with regard to the avoidance of acoustic weak points in broadcast production rooms
  • Consulting in the field of studio acoustics, improvement of acoustics in open-plan offices
  • Acoustic measurements - sound insulation, reverberation time, noise level, etc.
  • Measurement of noise emissions and advice on eliminating noise (e.g. caused by monitors, cameras, projectors, ventilation, etc.)
  • Room acoustic simulation with AUVIS, for the design of rooms on the basis of building plans and thus before the realization of a building project
  • Acoustic consulting and measurements for the construction of OB vans
  • Measurement and calculation of sound absorbers
  • Performing electroacoustic measurements to determine transmission and directivity measures, impulse responses, directivity characteristics, nonlinear distortion or noise floor of electroacoustic transducers (microphones, loudspeakers) as well as to assist in developments
  • Acoustic contract development (see reference project)
  • Realization of seminars and workshops for architects, civil engineers, studio planners and project managers


Reference Project - Cardioid Plane Microphone (KEM)

The KEM developed at IRT is a completely new microphone type with a disc-shaped directional characteristic (comparable to that of a loudspeaker line). The carefully tuned interconnection of individual microphones along a common axis creates an arrangement that has a directional distribution of the recording sensitivity that is useful for many applications (e.g. microphone techniques for  speakers, individually or collectively in discussion groups as well as groups in music and theatre performances). The KEM is also used with great success in the German Bundestag, at the lectern of the plenary hall of the Reichstag Berlin.

Distribution by Microtech Gefell GmbH

Your contact

Sebastian Goossens

Head of Department

Tel. +49 (0)89 32399-358

More information

KEM Kardioid-Ebenen-Mikrofon