In my opening remarks the acoustics and signal processing involved in active control will be reviewed: both for enhancing audio signals and for attenuating acoustic noise. The physical limits due to the geometry of practical arrays will be discussed, together with the signal processing design methods that can be used to implement robust practical arrays, whose performance approaches these geome...

1 Helsinki University of Technology Telecommunications and Multimedia Laboratory Otakaari 1, FIN-02150 ESPOO, Finland [email protected] 2 University of Westminster School of Electronic and Manufacturing Systems Engineering 115 New Cavendish Street, LONDON W1M 8JS, United Kingdom 3 Helsinki University of Technology Laboratory of Acoustics and Audio Signal Processing Otakaari 5A, FIN-02150 ESP...

Signal processing techniques allow us not only to compensate for the acoustics of a listening environment, but also to add special musical effects such as delay, echo, and reverb, if desired. The most common example is the audio equalizer that allows us to enhance the bass or treble content of an audio signal. What a listener hears in a room depends not only on the acoustics characteristics of ...

Room acoustics has a scientific interdisciplinary concept which will be further developed in future. During the last century, several dimensions of the overall listening impression in concert halls were identified which show a good correlation with corresponding objective measurement data. It can be summarized that the three most important factors (loudness, reverberance and spatial impression)...

This paper reviews techniques for the recording and reproduction of room sound fields used by the author in a variety of room acoustics research projects. The paper approaches this first through discussion of various criteria for assessing the usefulness of sound-field reproduction/simulation systems. The paper highlights issues in the recording of impulse responses for audio reproduction (thro...

This paper presents a new method performing real-time adaptive equalization of room acoustics in the frequency domain. The developed method obtains the frequency response of the room by means of the transparent insertion of a certain number of acoustic probe signals into the main audio spectrum. The opportunities for the insertion of tones are identified by means of a spectral analysis of the a...

GroupLoop is a browser-based, collaborative audio feedback control system for musical performance. GroupLoop users send their microphone stream to other participants while simultaneously controlling the mix of other users’ streams played through their speakers. Collaborations among users can yield complex feedback loops where feedback paths overlap and interact. Users are able to shape the feed...

A real-time virtual audio reality model has been created. The system includes model-based sound synthesizers, geometrical room acoustics modeling, binaural auralization for headphone or loudspeaker listening, and hiqh-quality animation. This paper discusses the following subsystems of the designed environment: The implementation of the audio processing softand hardware, and the design of a dedi...

The problem of sound field reconstruction is a subject of relevance in many branches of acoustics. In the audio industry, considerable research has been dedicated to the study of recording and reproduction systems that allow an accurate rendering of the spatial information that is considered to be an important component of the sound scene. This research activity is also encouraged by the increa...

Multichannel audio offers significant advantages for music reproduction, including the ability to provide better localization and envelopment, as well as reduced imaging distortion. On the other hand, multichannel audio is a demanding media type in terms of transmission requirements. Often, bandwidth limitations prohibit transmission of multiple audio channels. In such cases, an alternative is ...