公路绿化带降噪效应及其影响因素研究

噪音污染给人们生产生活带来不少影响,其中交通噪声又是噪声污染的重点。公路绿化带对衰减噪声有重要作用。公路绿化带不仅可以降低噪声,还可以改善生态环境,是一种经济、绿色的降噪方式。同时在不同的绿化模式下,降噪效果也不同。本文简单分析公路绿化带的降噪效果和影响降噪效果的因素。

城市边缘区土地利用变化及其降噪效应研究

土地利用及生态环境效应是全球环境变化研究的重要组成部分。以深圳市福田红树林国家级自然保护区及其周边地区为例,基于多源遥感影像进行土地利用变化分析,进而评估边缘区的生态敏感性,然后采用数学模拟的方法研究边缘区对交通噪声衰减效应的影响。结果表明:研究区在1983—2010年间土地利用变化以基围鱼塘向建设和交通用地转化为主,交通用地给保护区带来严重的噪声污染;声屏障和陆地绿地建成后,保护区噪声影响的鸟类生存适宜区23.86%增加到54.32%,降噪效应非常明显。

A speech enhancement algorithm to reduce noise and compensate for partial masking effect

To enhance the speech quality that is degraded by environmental noise,an algorithm was proposed to reduce the noise and reinforce the speech.The minima controlled recursive averaging(MCRA) algorithm was used to estimate the noise spectrum and the partial masking effect which is one of the psychoacoustic properties was introduced to reinforce speech.The performance evaluation was performed by comparing the PESQ(perceptual evaluation of speech quality) and segSNR(segmental signal to noise ratio) by the proposed algorithm with the conventional algorithm.As a result,average PESQ by the proposed algorithm was higher than the average PESQ by the conventional noise reduction algorithm and segSNR was higher as much as 3.2 dB in average than that of the noise reduction algorithm.