ISO 12124 pdf download

ISO 12124 pdf download.Acoustics — Procedures for the measurement of real-ear acoustical characteristics of hearing aids 1 Scope This International Standard specifies procedures and requirements for measuring the real-ear acoustical character- istics of hearing aids. Its purpose is to ensure that the same measurements made on a given hearing aid on a given human ear and a given hearing aid, following the procedures described and using equipment complying with the re- quirements of IEC 61 669, give substantially the same results. Measurements of real-ear acoustical characteristics of hearing aids which apply non-linear or analytical processing techniques are valid only for the test signals used and conditions employed. These measurements should be per- formed in accordance with the hearing aid manufacturer’s recommendations as they may require specific test signals or test conditions outside the scope of this International Standard. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publica- tions do not apply. However, parties to agreements based on this International Standard are encouraged to investi- gate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain reg- isters of currently valid International Standards. ISO 8253-2, Acoustics — Audiometric test methods — Part 2: Sound field audiometry with pure tone and narrow- band test signals . IEC 60942, Electroacoustics — Sound calibrators . IEC 61 669, Electroacoustics — Equipment for the measurement of real-ear acoustical characteristics of hearing aids 3 Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. 3.1 test signal acoustic signal at the field reference point 3.2 subject person in whose ear canal the hearing aid performance is being characterized 3.3 subject test position position with subject seated in a reproducible upright position with the head erect and the subject reference point lo- cated on the test axis at the working distance 3.4 subject reference point point bisecting the line joining the centres of the openings of the ear canals of the subject (at the junction between concha and ear canal) See Figure 1 . NOTE In cases of severe head shape abnormality or asymmetry, it may not be easy to determine the reference...