GB 23466-2025 Selection, use and maintenance of hearing protective equipment English, Anglais, Englisch, Inglés, えいご
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ICS 13.340.20 CCS C 73
National Standard of the People's Republic of China
GB 23466-2025
Replaces GB/T 23466-2009
Selection, Use and Maintenance of Hearing Protective Equipment
Issued on August 29, 2025
Implemented on September 1, 2026
State Administration for Market Regulation
Standardization Administration of China
Contents
Foreword
1 Scope
2 Normative References .
3 Terms and Definitions 4 Symbols
5 Types of Hearing Protective Equipment
6 Selection of Hearing Protective Equipment
7 Training, Precautions and Feedback
8 Maintenance
Appendix A (Informative) Typical Noise Types and Protection
Appendix B (Informative) Calculation Examples for Selecting Hearing Protectors
Appendix C (Informative) Fit Testing Methods for Hearing Protectors
Appendix D (Informative) Influence of Wearing Time on Protection Effectiveness
Appendix E (Informative) Training Requirements for Proper Use of Hearing Protectors
References
1 Scope
This standard specifies the selection methods and maintenance requirements for hearing protective equipment.
This standard applies to the selection, use and maintenance of hearing protective equipment in occupational noise workplaces.
This standard does not apply to protection against impulse noise.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute essential requirements of this standard. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 12903 Terminology for personal protective equipment
GBZ/T 189.8-2007 Measurement of Physical Factors in Workplace - Part 8: Noise
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 12903 and the following apply.
3.1 Hearing Protection Equipment / Hearing Protector
Personal protective equipment that protects hearing and prevents excessive noise stimulation.
[Source: GB 31422.1-2025, 3.1]
3.2 Earmuff
Hearing protector consisting of cups that press against or surround the ears and fit tightly around the head.
[Source: GB 31422.2-2025, 3.3]
3.3 Earplug
Hearing protector that is inserted into the ear canal or blocks the entrance to the ear canal.
[Source: GB 31422.1-2025, 3.3]
3.4 Sound Attenuation
For a given test signal, the difference in hearing thresholds between unprotected and protected conditions.
Note: Expressed in decibels (dB).
3.5 Over-Protection
When hearing protectors provide excessive sound attenuation, making it difficult for wearers to receive necessary sound signals, causing discomfort from environmental isolation.
3.6 Effective A-weighted Sound Pressure Level (Lp',AX)
For specific noise environments, when protection performance x is selected, the effective value of A-weighted sound pressure level when wearing hearing protectors, calculated by any of these methods: octave band method, HML method, or SNR method.
3.7 Protection Performance
The percentage of situations where the effective A-weighted sound pressure level when wearing hearing protectors is equal to or less than the predicted value.
Note 1: Typically set at 84% (equivalent to constant α=1).
Note 2: Refers to comprehensive conditions when wearing specific hearing protectors in particular noise environments.
3.8 Single Number Rating (SNRx)
When protection performance x and hearing protectors are selected, the value subtracted from C-weighted sound pressure level (Lp,C) to estimate effective A-weighted sound pressure level (Lp',AX).
3.9 Predicted Noise Level Reduction (PNRx)
When protection performance x and noise environment are selected, the difference between A-weighted sound pressure level (Lp,A) and effective A-weighted sound pressure level when wearing hearing protectors (Lp',AX).
3.10 Normalized 8-hour Equivalent Continuous A-weighted Sound Pressure Level (LEX,8h)
The equivalent sound level normalized to an 8-hour working day.
[Source: GBZ 2.2-2007, 11.1.7]
3.11 Normalized Weekly 40-hour Equivalent Continuous A-weighted Sound Pressure Level (LEX,w)
The equivalent sound level normalized to a 40-hour working week for special workplaces not following a 5-day work week.
[Source: GBZ 2.2-2007, 11.1.8]
4 Symbols
The symbols used in this standard shall conform to Table 1.
Table 1 Symbols
Symbol Definition
f Center frequency of octave band
LEX,8h 8-hour equivalent sound level
LEX,w Weekly 40-hour equivalent sound level
Lp,A A-weighted sound pressure level
Lp,C C-weighted sound pressure level
Lp',AX Effective A-weighted sound pressure level
5 Types of Hearing Protective Equipment
5.1 Classification by Design
5.1.1 Earmuffs and earplugs.
5.1.2 Earplugs include pre-formed earplugs, formable earplugs, and custom-molded earplugs. Formable earplugs are further divided into full-insertion and semi-insertion types.
5.2 Classification by Wearing Method
5.2.2 Earplugs include banded earplugs and non-banded earplugs.
5.3 Classification by Functional Mode
5.3.1 Basic hearing protectors (passive noise reduction only) and electronic hearing protectors with audio/communication functions (providing level-dependent features, active noise cancellation, or external audio input).
5.3.2 External audio input functions include non-safety audio input and safety audio input.
