title: Personal audio with a planar bright zone.
abstract: Reproduction of multiple sound zones, in which personal audio programs may be consumed without the need for headphones, is an active topic in acoustical signal processing. Many approaches to sound zone reproduction do not consider control of the bright zone phase, which may lead to self-cancellation problems if the loudspeakers surround the zones. Conversely, control of the phase in a least-squares sense comes at a cost of decreased level difference between the zones and frequency range of cancellation. Single-zone approaches have considered plane wave reproduction by focusing the sound energy in to a point in the wavenumber domain. In this article, a planar bright zone is reproduced via planarity control, which constrains the bright zone energy to impinge from a narrow range of angles via projection in to a spatial domain. Simulation results using a circular array surrounding two zones show the method to produce superior contrast to the least-squares approach, and superior planarity to the contrast maximization approach. Practical performance measurements obtained in an acoustically treated room verify the conclusions drawn under free-field conditions.
authors.affiliation: Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
authors.forename: Philip
authors.initials: P
authors.lastname: Coleman
authors.affiliation: Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
authors.forename: Philip J B
authors.initials: PJ
authors.lastname: Jackson
authors.affiliation: Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
authors.forename: Marek
authors.initials: M
authors.lastname: Olik
authors.affiliation: Bang & Olufsen A/S, Peter Bangs Vej 15, DK7600, Struer, Denmark.
authors.forename: Jan Abildgaard
authors.initials: JA
authors.lastname: Pedersen
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000669:Amplifiers, Electronic; D003198:Computer Simulation; D004867:Equipment Design; D006801:Humans; D016018:Least-Squares Analysis; D008962:Models, Theoretical; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014160:Transducers, Pressure