SS EN ISO 389-4 Ed. 1 (1999)现行
Acoustics - Reference Zero For The Calibration Of Audiometric Equipment - Part 4: Reference Levels For Narrow-band Masking Noise
出版：Standardiserings-Kommissionen I Sverige
专家解读视频
Defines reference levels for narrow-band masking noise presented by air conduction from an earphone in pure-tone audiometry. Data given is in terms of levels to be added to the reference equivalent threshold sound pressure levels for the corresponding pure-tone frequencies as given in ISO 389:1991 or ISO 389-2, respectively, when the masking earphone is placed on the appropriate acoustic coupler, ear simulator or artificial ear.
UNE EN ISO 389-4:1999 - Identical
NS EN ISO 389-4 Ed. 1 (1999) - Identical
I.S. EN ISO 389-4:1999 - Identical
ISO 389-4:1994 - Identical
UNI EN ISO 389-4:1999 - Identical
SN EN ISO 389-4:1999 - Identical
NF EN ISO 389-4:1999 - Identical
ONORM EN ISO 389-4:1999 - Identical
DIN EN ISO 389-4 (1999-07) - Identical
NEN EN ISO 389-4:1999 - Identical
BS EN ISO 389-4:1999 - Identical
NBN EN ISO 389-4:1999 - Identical
