Papers by Keyword: Engine Noise

Abstract: Environmental concerns due to aviation emissions and noise have resulted in introduction of emission and noise charges imposed by airports to airline operators. In order to assess the impact of emission and noise towards the airline's operating costs, this paper presents the initial work in developing an economic model and explains the validation and application of the direct operating cost (DOC) estimation used by the model. A comparison with another two DOC estimation methods has also been performed. The results indicate that the estimated cost is in a good agreement with the data from the public domain despite the differences with data from other estimation methods due to the variation of approach adopted by each model. Finally, an inclusion of environmental charges in DOC is also presented, which shows the amount is relatively small. Nonetheless, in order to ensure a sustainable airline operations, further actions in reducing aviation emission and noise are essential.

Abstract: Based on the measured and denoised vehicle engine noises, the sound quality evaluation (SQE) techniques in common use for A-weighting sound pressure level (SPL) and psychoacoustical parameters, such as loudness, sharpness and roughness, are performed and compared in this paper. The wavelet threshold shrinkage method is adopted for sound signal denoising. The comparisons suggest that the A-weighting SPL is not sufficient and can only be used as a reference in vehicle SQE, the psychoacoustical parameters can provide a complete description and more exactly reflect to the subjective feeling of vehicle noises, should be considered in vehicle designs.