On Multiple Sound Zones for Wideband Signals
Author
Andersen, Asger Heidemann
Term
4. term
Publication year
2014
Submitted on
2014-01-08
Pages
74
Abstract
Lydzoner går ud på at opdele et rum i områder, hvor lyden kan styres hver for sig, fx at afspille lyd i ét område, mens et andet holdes stille. Det opnås med et array af højttalere, der i fællesskab former, hvordan lyden breder sig i rummet. Mange eksisterende metoder antager meget simple lyde: rene toner med fast frekvens (sinusformede signaler). Denne antagelse passer dårligere til hverdagslyd som tale og musik, der indeholder mange frekvenser på én gang (bredbåndssignaler). Dette speciale undersøger, hvordan man kan skabe lydzoner for sådanne bredbåndssignaler. For at støtte undersøgelsen er der udviklet en software-ramme, der simulerer rumakustik med spejlkildemodellen, en teknik hvor vægrefleksioner beskrives ved at placere “spejl”-kopier af lydkilderne. Vi behandler både metoder, der tidligere er beskrevet i litteraturen, og nye tilgange. Vi viser, at overgangen fra rene toner til bredbåndslyd medfører udfordringer, som ikke opstår for simple signaler, og vi diskuterer måder at håndtere disse udfordringer på. Hovedresultatet er en lydzone-metode, der fungerer godt for bredbåndslyd.
Sound zones aim to divide a room into areas where audio can be controlled independently, for example playing sound in one area while keeping another quiet. This is achieved with an array of loudspeakers that work together to shape how sound spreads in the room. Many existing techniques assume very simple sounds: pure tones with a fixed frequency (sinusoids). That assumption does not hold for everyday audio like speech and music, which contain many frequencies at once (wideband signals). This thesis investigates how to create sound zones for such wideband signals. To support the study, we developed a software framework that simulates room acoustics using the mirror image model, a technique that represents wall reflections by placing “mirror” copies of the sound sources. We examine both methods previously discussed in the literature and new approaches, show why extending them from pure tones to wideband audio introduces additional challenges, and discuss ways to address those challenges. The main outcome is a sound zone method that performs well for wideband audio.
[This abstract was generated with the help of AI]
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