消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)：消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)主要用(yong)于降低空氣動(dong)(dong)力(li)噪(zao)聲(sheng)(sheng)(sheng)，如空調(diao)通(tong)風噪(zao)聲(sheng)(sheng)(sheng)。允許氣流通(tong)過，又可減(jian)少噪(zao)聲(sheng)(sheng)(sheng)傳播的裝置，通(tong)常稱(cheng)消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)。優(you)(you)良的消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)應具備下述性(xing)能(neng)(neng)：消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)能(neng)(neng)量大——噪(zao)聲(sheng)(sheng)(sheng)衰減(jian)明(ming)顯(xian)；空氣動(dong)(dong)力(li)性(xing)能(neng)(neng)好——力(li)損失小；結構性(xing)能(neng)(neng)優(you)(you)——抗(kang)腐(fu)蝕性(xing)、堅固(gu)耐用(yong)、體(ti)積小。按照(zhao)消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)原理可將消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)區(qu)分為阻性(xing)消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)、抗(kang)性(xing)消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)、阻抗(kang)復合消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)、小孔(kong)和多孔(kong)擴(kuo)散消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)等。

空(kong)間(jian)吸聲(sheng)體(ti)有平板形(xing)(xing)、球形(xing)(xing)和(he)圓(yuan)錐形(xing)(xing)等，其具體(ti)做法是(shi):平板形(xing)(xing)吸聲(sheng)體(ti)是(shi)將玻(bo)璃(li)纖維(wei)布縫成長方形(xing)(xing)的袋(dai)子，海口降噪設備(bei)，每袋(dai)裝超(chao)細玻(bo)璃(li)棉約1。5公斤，冷卻塔設備(bei)降噪項目，然后將袋(dai)子釘在(zai)木框(kuang)上，木框(kuang)四角(jiao)安裝1號羊(yang)眼作為吊掛(gua)之用。球形(xing)(xing)吸聲(sheng)體(ti)是(shi)用鐵絲編制而成的網球，冷卻塔隔音(yin)降噪設備(bei)批發，在(zai)網球內(nei)充(chong)填超(chao)細玻(bo)璃(li)棉。以上兩種空(kong)間(jian)吸聲(sheng)體(ti)可用鉛(qian)絲吊掛(gua)在(zai)頂(ding)棚(peng)(peng)內(nei)預埋或增設的吊鉤_L，距頂(ding)棚(peng)(peng)的高度為室(shi)內(nei)凈高的1/5~1/6，兩吸聲(sheng)體(ti)的水(shui)平間(jian)距以50厘米(mi)為宜。

噪(zao)(zao)(zao)聲(sheng)信號(hao)怎(zen)么處理及進行(xing)頻(pin)(pin)譜(pu)分析？1好進行(xing)頻(pin)(pin)譜(pu)分析確定(ding)噪(zao)(zao)(zao)聲(sheng)頻(pin)(pin)譜(pu)范圍(wei)，然后(hou)(hou)制作相(xiang)應的(de)濾波(bo)器(qi)，濾波(bo)器(qi)可以在采集(ji)前加一級低(di)通濾波(bo)器(qi)，機房降噪(zao)(zao)(zao)設備廠家(jia)，把(ba)高頻(pin)(pin)噪(zao)(zao)(zao)聲(sheng)去掉(diao)，不(bu)過對于粉(fen)紅噪(zao)(zao)(zao)聲(sheng)的(de)頻(pin)(pin)譜(pu)范圍(wei)很寬，幾乎(hu)整個頻(pin)(pin)域。這個只能(neng)(neng)優化不(bu)能(neng)(neng)去除(chu)，數(shu)字化后(hou)(hou)還可以加數(shu)字濾波(bo)器(qi)把(ba)噪(zao)(zao)(zao)聲(sheng)棄掉(diao)。具體(ti)為采集(ji)的(de)數(shu)據(ju)選擇一定(ding)的(de)長度也就是點數(shu)加漢(han)寧(ning)窗(chuang)后(hou)(hou)進行(xing)FFT，如果不(bu)加漢(han)寧(ning)窗(chuang)則默認為加了矩(ju)形(xing)窗(chuang)，不(bu)過這樣會(hui)(hui)造成部分頻(pin)(pin)譜(pu)泄(xie)露(lu)(lu)(lu)，當然漢(han)寧(ning)窗(chuang)也會(hui)(hui)泄(xie)露(lu)(lu)(lu)，但泄(xie)露(lu)(lu)(lu)會(hui)(hui)大大降低(di)。