對于室內(nei)高(gao)噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)的(de)、要求防(fang)爆、需(xu)散熱且換氣量(liang)較(jiao)大(da)、頻繁(fan)操作或維(wei)修的(de)，等(deng)多(duo)種大(da)型機(ji)械設備(bei)，都(dou)不宜(yi)采用(yong)隔聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)罩(zhao)的(de)形式，設置(zhi)一定(ding)(ding)高(gao)度的(de)室內(nei)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)屏障就可以(yi)起到一定(ding)(ding)的(de)降(jiang)(jiang)噪(zao)效果(guo)(guo)。為了防(fang)止(zhi)通過地板和(he)墻(qiang)壁等(deng)固(gu)體材(cai)(cai)料傳播(bo)的(de)振動噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)，在機(ji)器的(de)基礎(chu)和(he)地板、墻(qiang)壁聯結(jie)處設減振裝(zhuang)置(zhi)，如膠(jiao)墊、瀝青等(deng)。吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)材(cai)(cai)料吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)系數(shu)越(yue)(yue)大(da)，吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)面積越(yue)(yue)多(duo)，吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)效果(guo)(guo)越(yue)(yue)明顯，可以(yi)利(li)用(yong)吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)天(tian)花、吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)墻(qiang)體、空間吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)體等(deng)進行(xing)吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)降(jiang)(jiang)噪(zao)。在某些情況下，可以(yi)利(li)用(yong)一定(ding)(ding)的(de)材(cai)(cai)料和(he)裝(zhuang)置(zhi)，磚廠隔音降(jiang)(jiang)噪(zao)工程，把聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)源封閉，使(shi)其(qi)與(yu)周圍環境隔絕起來，黃山降(jiang)(jiang)噪(zao)工程，如隔聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)罩(zhao)、隔聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)間。隔聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)結(jie)構應該嚴密，以(yi)免產生共振影響隔聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)結(jie)果(guo)(guo)。

固體聲(sheng)(sheng)(sheng)(sheng)能(neng)傳(chuan)播到很遠的(de)(de)(de)地方，即隨著(zhu)距離(li)的(de)(de)(de)增(zeng)加(jia)衰減很小。對于(yu)因(yin)基礎向外傳(chuan)遞振動而產(chan)生的(de)(de)(de)固體聲(sheng)(sheng)(sheng)(sheng)可采(cai)取(qu)隔振方法加(jia)以(yi)控(kong)制(zhi)，而對于(yu)機組表面振動向外輻射的(de)(de)(de)噪(zao)聲(sheng)(sheng)(sheng)(sheng)可以(yi)利用阻尼減振的(de)(de)(de)辦法加(jia)以(yi)控(kong)制(zhi)。室(shi)外使(shi)用聲(sheng)(sheng)(sheng)(sheng)屏障時，可用磚(zhuan)墻(qiang)(qiang)、混凝土墻(qiang)(qiang)；室(shi)內使(shi)用時，可用鋼板、木板、塑料(liao)(liao)板、石膏板以(yi)及復合板等輕質材料(liao)(liao)。消(xiao)聲(sheng)(sheng)(sheng)(sheng)器(qi)是一種既(ji)能(neng)使(shi)氣流通過又能(neng)有效地降(jiang)(jiang)低噪(zao)聲(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)設備。通常可用消(xiao)聲(sheng)(sheng)(sheng)(sheng)器(qi)降(jiang)(jiang)低各種空(kong)氣動力(li)設備的(de)(de)(de)進出口或沿管道傳(chuan)遞的(de)(de)(de)噪(zao)聲(sheng)(sheng)(sheng)(sheng)。

采用(yong)吸(xi)(xi)聲(sheng)(sheng)材(cai)(cai)料(liao)裝飾在(zai)車(che)(che)間(jian)的(de)(de)內表(biao)面(mian)(mian)，如墻(qiang)壁(bi)和屋頂，或者(zhe)在(zai)車(che)(che)間(jian)內懸掛空(kong)間(jian)吸(xi)(xi)聲(sheng)(sheng)體，吸(xi)(xi)收輻(fu)射和反射聲(sheng)(sheng)能，使噪聲(sheng)(sheng)強(qiang)度減低。具有較好吸(xi)(xi)聲(sheng)(sheng)效果的(de)(de)材(cai)(cai)料(liao)有玻璃棉、礦渣(zha)棉、泡沫塑料(liao)、毛氈、棉絮、加氣混凝土、吸(xi)(xi)聲(sheng)(sheng)板(ban)、木絲板(ban)等。隔聲(sheng)(sheng)罩(zhao)(zhao)常用(yong)于(yu)小型噪聲(sheng)(sheng)源(yuan)，冷(leng)卻塔隔音降噪工(gong)程(cheng)，但一般機(ji)械設(she)(she)備(bei)(bei)在(zai)工(gong)藝上很難實(shi)現完全封閉(bi)，需(xu)考慮通風散熱，可設(she)(she)計為局(ju)部隔聲(sheng)(sheng)罩(zhao)(zhao)。為避免隔聲(sheng)(sheng)罩(zhao)(zhao)罩(zhao)(zhao)壁(bi)受聲(sheng)(sheng)源(yuan)激(ji)發而產生共振，罩(zhao)(zhao)內壁(bi)與機(ji)械設(she)(she)備(bei)(bei)之間(jian)留有空(kong)間(jian)，屋面(mian)(mian)設(she)(she)備(bei)(bei)降噪工(gong)程(cheng)，距離不得小于(yu)10cm。機(ji)械設(she)(she)備(bei)(bei)運轉產生的(de)(de)噪聲(sheng)(sheng)其傳(chuan)播方式有兩(liang)種(zhong)：一種(zhong)是(shi)在(zai)空(kong)氣中傳(chuan)播，稱(cheng)為空(kong)氣聲(sheng)(sheng)；另一種(zhong)是(shi)聲(sheng)(sheng)源(yuan)激(ji)發固體構件振動，這種(zhong)振動以彈性波的(de)(de)形式，通過基(ji)礎、廠(chang)房地板(ban)、墻(qiang)柱、機(ji)組表(biao)面(mian)(mian)向外輻(fu)射噪聲(sheng)(sheng)，即固體聲(sheng)(sheng)。