1 - AS/NZS 1270:1999 ACOUSTICS-HEARING PROTECTORS
4 - PREFACE
5 - CONTENTS
6 - SECTION 1 SCOPE AND GENERAL
6 - 1.1 SCOPE
6 - 1.2 APPLICATION
6 - 1.3 REFERENCED DOCUMENTS
6 - 1.4 DEFINITIONS
6 - 1.4.1 Acoustic helmet
6 - 1.4.2 Diffuse sound field
6 - 1.4.3 Disposable earplug
6 - 1.4.4 Ear canal cap
6 - 1.4.5 Earmuff
6 - 1.4.6 Earplug
6 - 1.4.7 Hearing protector
7 - 1.4.8 Occluded-ear threshold of hearing
7 - 1.4.9 Open-ear threshold of hearing
7 - 1.4.10 Pink noise
7 - 1.4.11 Real-ear attenuation
7 - 1.4.12 Reference point
7 - 1.4.13 Reverberation time
7 - 1.4.14 Suspension system
7 - 1.4.15 Test signal
7 - 1.4.16 Threshold of hearing
7 - 1.4.17 User formable earplug
8 - SECTION 2 GENERAL REQUIREMENTS
8 - 2.1 DESIGN AND CONSTRUCTION
8 - 2.1.1 General
8 - 2.1.2 Earmuffs
8 - 2.2 MATERIALS
8 - 2.3 WEARER INFORMATION
8 - 2.3.1 Information in or on the packaging
9 - 2.3.2 Information on the packaging
9 - 2.3.3 Information with each packaged pair of earplugs
9 - 2.4 MARKING
10 - SECTION 3 PERFORMANCE
10 - 3.1 PHYSICAL REQUIREMENTS
10 - 3.2 TEST PROCEDURES
10 - 3.2.1 General
10 - 3.2.2 Examination
10 - 3.2.3 Preparation
10 - 3.2.4 Clamping force test
12 - 3.2.5 Dry heat test
12 - 3.2.6 Low temperature drop test
13 - 3.2.7 Cleaning
13 - 3.2.8 Second measurement of clamping force
13 - 3.2.9 Attenuation
14 - SECTION 4 METHOD FOR MEASUREMENT OF THE REAL-EAR ATTENUATION OF HEARING PROTECTORS
14 - 4.1 SCOPE OF SECTION
14 - 4.2 PHYSICAL REQUIREMENTS OF THE TEST FACILITY
14 - 4.2.1 Test signals
14 - 4.2.2 Test site
17 - 4.2.3 Test equipment
18 - 4.3 TEST SUBJECTS
18 - 4.3.1 Conditions for subject acceptance/dismissal
18 - 4.3.2 Previous experience with hearing protectors
19 - 4.3.3 Anatomical features
19 - 4.3.4 Otoscopic inspection
19 - 4.3.5 Age
19 - 4.3.6 Sex
19 - 4.3.7 Maximum hearing levels
19 - 4.3.8 Minimum hearing levels
19 - 4.3.9 Threshold variability
19 - 4.3.10 Spectacles and jewellery
19 - 4.3.11 Literacy
20 - 4.3.12 Number of subjects
20 - 4.3.13 Maximum number of tests per subject
20 - 4.3.14 Exceptions
20 - 4.4 PRODUCT SAMPLES
20 - 4.4.1 General
20 - 4.4.2 Custom-moulded earplugs
20 - 4.4.3 Product instructions
20 - 4.4.4 Variable position headbands
20 - 4.5 TEST PROCEDURE
20 - 4.5.1 Preliminary set-up
21 - 4.5.2 Test method
23 - 4.5.3 Re-determination of thresholds
23 - 4.6 COMPUTATION OF REAL-EAR ATTENUATION
23 - 4.7 COMPUTATION OF CLASS OF HEARING PROTECTOR
24 - 4.8 TEST REPORT
25 - APPENDIX A - CALCULATION OF SLC80 AND CLASS OF HEARING PROTECTOR
25 - A1 GENERAL
25 - A2 CALCULATION OF SLC80
25 - A3 EXAMPLE OF SLC80 CALCULATION
25 - A3.1 Step 1
25 - A3.2 Step 2
26 - A4 DETERMINATION OF CLASS
26 - A5 BIBLIOGRAPHY
27 - APPENDIX B - QUALITY CONTROL TESTS
27 - B1 SCOPE
27 - B2 QUALITY CONTROL TESTS
27 - B3 COMPARISON WITH THE ORIGINAL CLAMPING FORCE TEST VALUE
28 - APPENDIX C - COUNTERBALANCING