نتایج جستجو برای: acoustic noise
تعداد نتایج: 271819 فیلتر نتایج به سال:
Background and aims The influences of Low Frequency Noise (LFN) on mental performance have been the objectives of many papers in recent years. Many researchers believe that the LFN even at low pressure levels has impacts on mental performance. In the present work the influences of LFN and Reference Noise (RN) at two different sound pressure levels (45 & 65 dBA) on mental performances of co...
The RV Investigator is Australia’s new noise quietened Marine National Facility (MNF) vessel built to comply with the DNV silent-R specification. This radiated noise specification was based on the ICES 209 CRR specification designed with the main goal of minimising vessel avoidance for fisheries surveys. Noise quietening was specified for RV Investigator to improve the acoustic detection of ins...
In this paper, we describe a parallel decoding-based ASR system developed of ATR that is robust to noise type, SNR and speaking style. It is difficult to recognize speech affected by various factors, especially when an ASR system contains only a single acoustic model. One solution is to employ multiple acoustic models, one model for each different condition. Even though the robustness of each a...
background: noise pollution is currently a major risk factor in industries in both developed and developing countries . the present study assessed noise pollution in the knitting industry in iran in 2009 and presented a control method to reduce the rate of noise generation. methods: the overall noise level was estimated using the network environmental noise assessment method in sina poud textil...
The acoustic problem of the split gradient coil is one challenge in a Magnetic Resonance Imaging and Linear Accelerator (MRI-LINAC) system. In this paper, we aimed to develop a scheme to reduce the acoustic noise of the split gradient coil. First, a split gradient assembly with an asymmetric configuration was designed to avoid vibration in same resonant modes for the two assembly cylinders. Nex...
An acoustic survey of secondary schools in England has been undertaken. Room acoustic parameters and background noise levels were measured in 185 unoccupied spaces in 13 schools to provide information on the typical acoustic environment of secondary schools. The unoccupied acoustic and noise data were correlated with various physical characteristics of the spaces. Room height and the amount of ...
Hands-free devices, such as mobile phones, are perhaps one of the most prominent applications of acoustic echo cancellation systems. They are often used in a noisy enclosed environment. Therefore, the recorded near-end speech will also contain reverberation and background noise, which degrade the fidelity and intelligibility of speech. In the last two decades postprocessors have been developed ...
Ventilation systems installed in buildings usually generate low-frequency noise because the passive silencers commonly used to attenuate the ventilation noise are not effective in the lowfrequency range. A method proven to effectively reduce low-frequency noise in a wide variety of applications is active noise control (ANC). A feedforward ANC system applied to duct noise normally uses a referen...
Noise generated in flow duct propagates extensively through the connected ductwork. Its propagation through the outlets would contribute to indoor acoustic discomfort and results in environmental problem. Silencers with acoustic lining are commonly adopted for noise mitigation in flow duct. Researchers have been devoting many numerical efforts in assessing the performance of a liner design. In ...
Introduction Magnetic Resonance Imaging (MRI) scanners are popular medical diagnostic devices providing useful information about patients in a noninvasive manner. However, a disadvantage of MRI is the high level of acoustic noise generated during scanning, which is caused by the Lorentz forces acting on the gradient coils bound within an epoxy resin cylinder. As the gradient current switches di...
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