NEN EN ISO 389-4 : 1999
Current
The latest, up-to-date edition.
12-01-2013
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.
Access your standards online with a subscription
Features
-
Simple online access to standards, technical information and regulations.
-
Critical updates of standards and customisable alerts and notifications.
-
Multi-user online standards collection: secure, flexible and cost effective.