Masking zaj duab xis, ib yam ntawm cov khoom siv npog ntsej muag, feem ntau yog siv rau tsheb, nkoj, tsheb ciav hlau, tsheb tavxij, rooj tog zaum, thiab lwm yam khoom thaum siv tshuaj pleev xim, pleev xim pleev xim, pleev xim pleev xim thiab kho kom zoo nkauj sab hauv, cov khoom muab faib ua qhov kub thiab txias ntawm chav tsev ( raws li cov txheej txheem tsim khoom tom qab cov xim yog txau tom qab qhov kub thiab ib puag ncig sib txawv). Txhim khu kev ua tau zoo ntawm kev tsim khoom, txuag kev ua haujlwm thiab txhim kho qhov tshwm sim uas cov xim yuav xau thaum siv cov ntawv xov xwm khib nyiab los thaiv cov xim yav dhau los.
