NEN EN ISO 389-3 : 2016

Foreword
Introduction
1 Scope
2 Normative references
3 Definitions
4 References equivalent threshold force levels (RETFLs)
5 Test conditions and requirements
Annex A (informative) Note on the derivation of RETFL values
Annex B (informative) Guidance on the application of the
reference zero to the calibration of bone-conduction audiometers
Annex C (informative) Interim differences in reference
equivalent threshold force levels between forehead and
mastoid location of vibrator
Annex D (informative) Bone-conduction threshold of hearing
for frequencies below 250 Hz
Annex E (informative) Bibliography
Annex ZA (normative) Normative references to International
Publications with their relevant European publications
Table 1 Reference equivalent threshold force levels (RETFLs)
          for location of the vibrator on the mastoid bone
Table A.1 Investigations on RETFL values
Table C.1 Interim differences in reference equivalent threshold
          force levels between forehead and mastoid location of
          vibrator
Table C.2 Investigations of RETFL (forehead) minus RETFL
          (mastoid values)
Table D.1 Reference equivalent threshold force levels for
          mastoid location and differences in reference
          equivalent threshold force levels between forehead
          and mastoid location of vibrator

Defines the following data applicable to the calibration of bone vibrators for puretone bone-conduction audiometry: a) reference equivalent threshold vibratory force levels (RETVFL), corresponding to the threshold of hearing of young otologically normal persons by bone-conduction audiometry; b) essential characteristics of the bone vibrator and the method of coupling to the test subject, and to the mechanical coupler; c) essential characteristics of the masking noise and the baseline masking noise level applied to the ear not under test.