An analytical approach to local sound field synthesis using linear arrays of loudspeakers

Abstract

Methods like Wave Field Synthesis aim at the synthesis of a given desired sound field over a large receiver area. Practical limitations lead to considerable artifacts commonly referred to as spatial aliasing. Above a given frequency these artifacts are apparent anywhere in the receiver area when linear arrays of secondary sources are considered. This paper presents an analytical approach based on the Spectral Division Method which achieves an accuracy of the synthesized sound field which is significantly higher than in conventional approaches in a limited target zone. This local increase in accuracy is achieved via a manipulation of the spatial bandwidth of the secondary source driving function.

Broadband multizone sound rendering by jointly optimizing the sound pressure and particle velocity

“…In recent years, much research effort has also been invested in personalized audio reproduction, i.e., synthesizing individualized acoustic scenes for multiple listeners in different areas of the reproduction room [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. A prominent use case is given in cars, where the driver could listen to the information provided by a navigation system while all passengers can enjoy their favorite audio content.…”

“…A prominent use case is given in cars, where the driver could listen to the information provided by a navigation system while all passengers can enjoy their favorite audio content. The different approaches to multizone sound reproduction vary widely: Some methods are based on WFS and utilize analytically derived driving functions for the loudspeakers [10,11,16,26]; others exploit the fact that sound fields can be described using orthogonal basis functions [12,13,17], such as cylindrical or spherical harmonics; there are also different multi-point approaches, where the sound pressure [8], the acoustic energy/contrast between the different zones [7,9], or both quantities are optimized [18]. Multi-point techniques often use a description of the sound field in the spatial domain, but they can also be formulated in the modal domain [13], i.e., using basis functions.…”

Robust Sound Field Reproduction against Listener^|^apos;s Movement Utilizing Image Sensor

“…As a result, the filter power at high frequencies increases and the reproduced sound field emphasizes sounds with high frequency. To prevent the spectral overlap, spatial bandwidth limitation of the driving function of secondary sources, so-called local sound field synthesis, has been proposed [2]. The reproduced sound field has high reproduction accuracy only in a limited region corresponding to the limited spatial bandwidth.…”

“…where j is the imaginary unit, k x is the wavenumber in the x-direction, c is the speed of sound, ω is the angular frequency, y R is the reference listening distance H (2) 0 (·) denotes the zeroth-order Hankel function of the second kind and K 0 (·) denotes the zeroth-order modified Bessel function of the second kind in Eq. (1).…”

“…This method can be realized with a simple system such as a linear loudspeaker array, and the technique known as local sound field synthesis [2] can be smoothly applied to the method. By applying this technique to the SDM, we can reproduce the sound field in a limited target region with high accuracy by limiting the spatial bandwidth of the driving function in the wavenumber domain.…”