RESEARCH ON AUDIO SIGNAL PROCESSING
Signals and Systems, Uppsala University
Industrial collaboration partner:
Dirac Research AB
Article (in Swedish) on some of our audio research in Ergo, May 16, 2012.
Room Correction and Sound Field Control
We investigate the design and analysis of digital filters for various audio reproduction application:
One characteristic of the design and analysis of audio signal processing system is that the ultimate criterion is not easily captured objectively: It constitutes a perceptual quality experienced by a listener, or a group of listeners. It is therefore crucial to investigate the perceptual results of various compensation and sound control schemes. Our aim is to better objectively characterize differences in subjective experience and to better capture the perceptual effect of different audio compensation schemes.
Active Noise Control
In our research effort on active noise control, we investigate ways to use digital audio systems in cars and trucks also for active noise control: The bass loudspeakers of the sound system then produce anti-noise, which cancels low-frequency engine noise or road noise at the driver or passenger positions. This reduces the cost and complexity as compared to stand-alone solutions.
The Signals and Systems group has led the design and construction of an anechoic chamber, designed for both acoustic and radio-frequency measurements, at the Ångtröm Laboratory at Uppsala University. The chamber and measurement equipment was funded by the Knut and Alice Wallenberg Foundation. The chamber was finalized in 2009 and has a size of (LxWxH) 11.9 x 9.6 x 6.1 m. It constitutes a well damped environment in which experiments can be performed for the purpose of evaluating the effectiveness of different algorithms.
The audio equipment consists of sixteen active ATC loudspeakers, eight DPA microphones and two Prism Orpheus sound cards having in total eight inputs and sixteen outputs. The chamber, together with the equipment, thus constitutes an excellent testbed for conducting controlled acoustic experiments.