median of sounds level

同义词释义

1)median of sounds level,噪声声级的中间值2)noiseratingnumbers , NRN,噪声级数，噪声分级值，NRN3)medium of sound level,声级中值4)noise rating number,噪声分级值(NR值)5)noise grade A,噪声A声级6)equivalent sound level,等值噪声等级