Loudspeaker arrays are increasingly being used in a variety of applications where there is a restriction on the electrical power consumption and the array must be robust to changes in the acoustic environment. Previous work has demonstrated that the efficiency and robustness of a two-source endfire loudspeaker array can be improved by acoustically coupling the two loudspeakers via a common encl...

In some large enclosures, such as underground stations or factory halls, which involve long reverberation time, low signal-to-noise ratio, public address systems are often used to improve the speech intelligibility. Nevertheless, too many distributed loudspeaker systems suffer an inappropriate use of loudspeakers. This can lead to an imperfect uniformity of audience coverage decreasing the spee...

Near-field compensated higher order Ambisonics (HOA) is an approach to the physical synthesis of sound fields. The typical interpretation of the modern HOA approach is that the sound field to be synthesized and the spatio-temporal transfer function of the employed loudspeakers are expanded into series of spherical harmonics in order to determine the loudspeaker driving signals for spherical arr...

Optimal arrangement of loudspeakers in space is an important topic for the design of personal audio system with less number of loudspeakers. The acoustic contrast based on the ratio of acoustic energies(L2 norms) has been used for the maximization of sound pressure level difference between two different regions, but it only determines optimal driving functions of loudspeakers of which positions...

For rectangular rooms with symmetric loudspeaker arrangements, full room equalization can be achieved at low frequencies, as demonstrated by previous research. The method is based on generating a plane wave that propagates along the room. However, often the room is not rectangular, and/or a symmetric loudspeaker setup cannot be assured, leading to a deteriorated equalization performance. In add...

Cumulative spectral decay of a loudspeaker showing the transient behavior.

The emerging applications of the parametric loudspeaker, such as 3D audio playback systems, require both controllable directivity and high fidelity at the audible frequency (a.k.a. the difference frequency). Although phased array techniques have been applied and proven adequate to steer the mainlobe of a parametric loudspeaker, and preprocessing methods have been studied to reduce the harmonic ...

Audibility of ultrasonic components contained in a harmonic complex tone were investigated. The level of the components varied adaptively and the maximum level investigated was 80 dB SPL / component. All subjects distinguished between sounds with and without ultrasounds only when the stimulus was presented through a single loudspeaker. When the stimulus was divided into six bands of frequencies...