BS EN ISO 8253-2:2009 PDF

BS EN ISO 8253-2:2009 Acoustics. Audiometric test methods. Sound field audiometry with pure-tone and narrow-band test signals BS EN ISO 8253-2 specifies relevant test signal characteristics, requirements for free, diffuse, and quasi-free sound fields, and procedures for sound field audiometry using pure tones, frequency-modulated tones or other narrow-band test signals presented by means of one or more loudspeakers. The primary purpose is the determination of hearing threshold levels in the frequency range 125 Hz to 8 000 Hz, but this range can be extended to 20 Hz to 16 000 Hz. BS EN ISO 8253-2 does not include specifications for the use of hand-held loudspeakers. Speech as a test signal is not covered. BS EN ISO 8253-2 is to ensure that tests of hearing, using sound field audiometry, give a high a degree of accuracy and reproducibility as possible. Examples of graphical representations of the results are given in Annex A. Contents of BS EN ISO 8253-2: Foreword Introduction 1 Scope 2 Normative references 3 Terms and definitions 4 Test signal characteristics 4.1 General 4.2 Pure tones 4.3 FM tones 4.4 Narrow bands of noise4. 4.5 Harmonic distortion 4.6 Signal gating 4.7 Signal level control 4.8 Means and scales for calibration 5 Sound field characteristics 5.1 General 5.2 Free sound field 5.3 Diffuse sound f...