GOST R ISO 389-4:2011 确保测量一致性的国家体制.听力测定设备的校准用参考零点.第4部分:窄频带遮蔽噪声的基准级
State system for ensuring the uniformity of measurements. Acoustics. Reference zero for the calibration of audiometric equipment. Part 4. Reference levels for narrow-band masking noise