Car cabin personal audio: acoustic contrast with limited sound differences

The generation of independent or personal listening zones is of significant interest in the car cabin environment. As such there are a number of methods of optimizing loudspeaker arrays to achieve personal audio reproduction. The optimization methods currently in the literature generally have a trade-off between the level of acoustic contrast between the bright and dark zones and the variance of the sound pressure within the bright zone. A high level of variance in the bright zone may produce a subjectively poor performance and although this may be overcome using the least squares or acoustic contrast with planarity control methods, they are generally non-trivial to setup to achieve both a high level of acoustic contrast and a low level of variance. This paper proposes a new optimization method which maximizes the acoustic contrast with a constraint that limits the sound differences within the bright zone and is relatively straightforward to setup. The performance of the proposed optimization method is compared to acoustic contrast maximization, least squares and acoustic contrast maximization with planarity control methods through a series of simulations of a car cabin personal audio system

A study in student attitude change resulting from non-sequential curriculum modification measured by semantic differential

Abstract not availabl

High accuracy estimation technique of structural vibration by virtual sensing

Virtual sensing is a method to estimate unobservable or unmeasurable state variables by combining exsisting measurement data with model information. When FE model is applied to the virtual sensing, vibration response data estimated at all nodes. When it enables to estimate the vibration response data at all nodes, for example, it will be possible to simulate sound radiation from mechanical structure with the vibration response data. In this paper, it is illustrated how to estimate high accuracy vibration response data. It then examines the effect of excitation force on the vibration estimation results. Based on the results of this verification, a method to improve the accuracy of vibration response estimation is proposed. It also tests the relationship with accuracy of estimated vibration data and the difference between real and estimated location of excitation force. Finally, it tests how the quality of estimation for sound radiation