Audio Production
5.1 to 2.0 Audio Downmix-Algorithm
IRT developed a new downmix algorithm which is based on comprehensive investigations on quality aspects in downmixing a 5.1 to a 2.0 format. With this new algorithm it is possible to prevent or to compensate to a high extent the effects which usually lead to impairments of the acoustic stereo-downmix quality. more
Acoustic Summing Algorithm
Whenever several microphones pick up the same acoustic source, mixing involves the risk of cancellations caused by delay differences: the comb filter effect. The naturalness of the sound is gone: the trumpet twangs, the choir sounds metallic.
In order to prevent this, one had so far always to carefully make sure that there is not too much cross talk of sound portions to other microphones. Thereby, not only the possibilities of the tonal design are limited, but sometimes compromises become unavoidable. more
Binaural Room Synthesis
IRT’s BRS system offers virtual reproduction of measured or modelled loudspeaker monitoring situations with perfect accuracy. Using BRS, one is able to copy the listening experience of a 5.1 loudspeaker setup in a real room to a headphone system.
During the past few years IRT has optimised the BRS algorithm and technology within numerous research and development projects. Throughout the world the performance of IRT’s BRS solution is unrivalled. more
Microphone Tracking System
For the past two years a project group at the IRT has been conducting research on how the audio portion of football broadcasts could be enhanced by including specific ball sounds in order to more closely integrate television viewers into the events taking place on the field. The scientists have now found a solution in quickly and automatically tracking directional microphones positioned at special locations. The original idea is meanwhile turned into a prototype (patent pending). First tests were already successfully conducted in Munich's soccer stadium, the Allianz Arena, and in Berlin’s Olympic Stadium during an international match. more
Quality Measurement of Audio Codecs
Modern audio coding methods with data reduction work usually, subject to the application, with very varying bit rates. With lossy methods the reduction of bit rate is accompanied by a directly related reduction of quality.
Objective techniques for the measurement of the audio quality of special audio coding methods or cascading chains (multiple encoding and decoding while applying same or different audio coding methods within a transmission chain) until today deliver results which are not sufficiently reliable, particularly in the case of new coding methods. Therefore, subjective testing methods in the form of hearing tests, in support of objective measurement methods, are imperative for correct quality assessment. more
