Quantifying sound quality in loudspeaker reproduction

We present PREQUEL: Perceptual Reproduction Quality Evaluation for Loudspeakers. Instead of quantifying the loudspeaker system itself, PREQUEL quantifies the overall loudspeakers' perceived sound quality by assessing their acoustic output using a set of music signals. This approach introduces a major problem: subjects cannot be provided with an...

Directional loudspeaker arrays for acoustic warning systems with minimised noise pollution

This paper describes numerical and experimental results of beamforming algorithms for generation of directional sound. The intended application is a sound source for cars with the objective to warn vulnerable road users while minimising noise pollution. Nowadays, sensors exist which are able to reveal the position of the vulnerable road users,...

Direct measurements of acoustic damping and sound amplification in corrugated pipes with flow

The flow-induced pulsations in corrugated pipes result from a feedback loop between an acoustic resonator and the noise amplification at each shear layer in the axisymmetric cavities forming the corrugations. The quality factor of the resonator is determined by the reflection coefficients at the ends of the corrugated pipe and by the damping in...

A low density, high stiffness flat loudspeaker with improved sound frequency response

This paper presents a novel flat loudspeaker with improved sound frequency response. Flat loudspeakers provide advantages of compact dimensions and high durability. Known flat loudspeaker technology is based on high modal density. However, the resonances in the panel are complex and difficult to control, which often leads to complicated...

A-weighted equivalent sound level as a predictor of the annoyance caused by road traffic consisting of various proportions of light and heavy vehicles

A laboratory study was conducted to examine the relationship between noise annoyance and the proportion of heavy vehicles in a mixture of trucks and passenger cars. Twenty normal-hearing subjects were asked to judge the annoyance caused by the sounds from a continuous stream of vehicles, assuming they were exposed to it at home on a regular...