Effect of waste materials on acoustical properties of semi-dense asphalt mixtures

Among the urban societal burdens rolling noise generation from tire pavement interaction and urban waste stand apart. Many urban waste materials can be used in pavements with comparable mechanical performance. Noise-related pavement characteristics such as porosity, sound absorption and surface texture, were measured for semi-dense low noise pavement mixtures using urban waste materials namely: recycled concrete aggregates, crumb rubber, polyethylene terephthalate and polyethylene. The results show that the use of these materials is a viable sustainable option for low noise pavements, however that may affect the noise reduction properties. With values around 0.2 at 1000 Hz, the sound absorption of all the mixtures is relatively low and the use of mean profile depth (MPD) alone is not enough to characterize the noise reduction properties. Surface texture was altered in different degrees depending on the waste material used. The results presented can aid in policy pertaining to noise abatement and waste reduction

Towards a general framework for including noise impacts in LCA

Industrial Ecolog

Evaluating a visual-acoustic simulation for wind park assessment

AbstractThe implementation of wind parks often fails due to lack of public acceptance. Visual-acoustic landscape simulations of wind parks offer a potential instrument for public participation, allowing experiencing the visual and the acoustic landscape impact. However, before such simulations can be implemented in practice, they need to be validated.In this article, we develop and apply an approach to evaluate visual-acoustic simulations for assessing wind park perceptions. The approach compares whether simulations generate similar reactions of respondents as recordings of the same environments. The survey participants made a visual and an acoustic assessment of the landscape represented by recordings and by simulations.The results show that there was nearly no difference in the rating of the annoyance of wind turbine noise between the recordings and the simulation. With regard to the visual landscape assessment the ratings based on the simulations were lower than the ones based on the recordings. The approach indicates aspects of the simulation that differ compared to the recording, such as coherent coloring and animation of landscape elements. The rating differences between the recordings and the simulations of both, the visual and the acoustic perception have to be considered when using the simulations for further studies.Overall, the described approach was successfully applied and contributes to validity testing methods. However, this is a preliminary and exploratory study. A complete test of validity should compare the simulations to the actual environment, which should be further studied

Evaluation of Auralization and Visualization Systems for Railway Noise Scenes

By directly addressing the hearing sensation, auralization is an intuitive means for the assessment and communication of noise scenarios. Authenticity can be fu1iher improved by offering visual information. Currently, various auralization and visualization systems exist, that differ with respect to their sound and image signal generation as well as their reproduction strategy. Within the past few years, the entertainment indushy has launched several virtual reality (YR) products such as head-mounted displays or game engines that appear attractive for applications in environmental sound auralization. This contribution gives an overview of current VR systems and inti·oduces evaluation criteria for comparison and assessment. Focus here is on the application to different railway noise scenes. This involves the generation of stimuli for experimental studies and the use as a demonstrator. To achieve maximal flexibility with respect to scenarios and the reproduction systems, the synthesis of sound and images on the basis of on an object-based approach is suggested.Aircraft Noise and Climate Effect

Multi-system neurorehabilitative strategies to restore motor functions following severe spinal cord injury

Severe spinal cord injury (SCI) permanently abolishes motor functions caudal to the lesion. However, the neuronal machinery sufficient to produce standing and stepping is located below most SCI, and can be reactivated with training. Therefore, why do rats and humans fail to regain significant levels of motor control after a severe SCI? In this review, we argue that the lack of sustainable excitability in locomotor circuitries after SCI prevents the emergence of functional motor states during training, thus limiting the occurrence of activity-dependent plasticity in paralyzed subjects. In turn, we show that spinal rats trained with combinations of epidural electrical stimulation and monoamine agonists, which promote locomotor permissive states during rehabilitation, can regain coordinated stepping with full weight bearing capacities in the total absence of supraspinal influences. This impressive recovery of function relies on the ability of spinal circuitries to utilize multisensory information as a source of control and learning after the loss of brain input. We finally discuss the implication of these findings for the design of multi-system neurorehabilitative interventions capable of restoring some degree of function in humans with severe SCI