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GB/T 4854.4-1999 PDF English


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GB/T 4854.4-1999English120 Add to Cart 0-9 seconds. Auto-delivery. Acoustics. Reference zero for the calibration of audiometric equipment. Part 4: Reference levels for narrow-band masking noise
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GB/T 4854.4-1999: PDF in English (GBT 4854.4-1999)

GB/T 4854.4-1999 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 17.140.01 A 42 eqv ISO 389-4:1994 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 4: Reference Levels for Narrow-band Masking Noise ISSUED ON: MARCH 08, 1999 IMPLEMENTED ON: SEPTEMBER 01, 1999 Issued by: The State Bureau of Quality and Technical Supervision Table of Contents Foreword ... 3  ISO Foreword ... 5  Introduction ... 6  1 Scope ... 7  2 Normative References ... 7  3 Definitions ... 8  4 Specifications ... 9  Annex A (informative) Notes on the Derivation of the Reference Levels ... 11  Annex B (informative) Bibliography ... 13  Foreword This Standard equivalently adopts international standard ISO 389-4:1994 Acoustics – Reference Zero for the Calibration of Audiometric Equipment - Part 4: Reference Levels for Narrow-band Masking Noise. This standard makes unified provisions for masking noise level in pure tone testing. It will actively promote the standardization of acoustic technology, promote the acoustic development and international exchanges. This is the 4th standard of the standard series Acoustics - Reference Zero for the Calibration of Audiometric Equipment. This standard series GB/T 4854 has seven standards under the general topic Acoustics - Reference Zero for the Calibration of Audiometric Equipment, which are: GB/T 4854.1 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 1: Reference Equivalent Threshold Sound Pressure Levels for Pure Tones and Supra-aural Earphones GB/T 16402 Acoustics - Reference Equivalent Threshold Sound Pressure Levels for Pure Tones and Insert Earphones GB/T 4854.3 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 3: Reference Equivalent Threshold Force Levels for Pure Tones and Bone Vibrators GB/T 4854.4 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 4: Reference Levels for Narrow-band Masking Noise GB/T 4854.5 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 5: Reference Equivalent Threshold Sound Pressure Levels for Pure Tones in the Frequency Range 8 kHz to 16 kHz GB/T 4854.6 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 6: Reference Hearing Threshold Levels for Test Signals of Short Duration GB/T 4854.7 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 7: Reference Threshold of Hearing under Free-field and Diffuse- field Listening Conditions NOTE: 1. When the Part 2 in the series was formulated, the standard series has not been formed. When GB/T 16402 is revised, the standard number will be modified into GB/T 4854.2. Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 4: Reference Levels for Narrow-band Masking Noise 1 Scope This Standard specifies reference levels for narrow-band masking noise presented by air conduction from an earphone in pure-tone audiometry. The data are given in terms of levels to be added to the reference equivalent threshold sound pressure levels for the corresponding pure-tone frequencies as specified in GB/T 4854.1 or GB/T 16402, respectively, when the masking earphone is placed on the appropriate acoustic coupler, ear simulator or artificial ear. Data are given for noise bandwidths of one-third and one-half octaves. NOTE: some notes on the derivation of the reference levels are given in Annex A. 2 Normative References The following standards contain provisions which, through reference in this text, constitute provisions of this Standard. At the time of publication, the editions indicated where valid. All standards are subject to revision, and parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. GB/T 4854.1-1999 Acoustics - Reference Zero for the Calibration of Audiometric Equipment - Part 1: Reference Equivalent Threshold Sound Pressure Levels for Pure Tones and Supra-aural Earphones (eqv ISO 389-1:1991) GB/T 7341.1-1998 Audiometers - Part 1: Pure-tone Audiometers (idt IEC 645-1:1992) GB/T 7342-1987 IEC Provisional Reference Coupler for the Calibration of Earphones Used in Audiometry (eqv IEC 303:1970) GB/T 7614-1987 An Artificial Ear of Wide Band Type for the Calibration of Earphones Used in Audiometry (eqv IEC 318:1970) GB/T 16402-1996 Acoustics - Reference Equivalent Threshold Sound Pressure Levels for Pure Tones and Insert Earphones (eqv ISO 389-2:1994) SJ/Z 9144-1987 IEC Reference Coupler for the Measurement of Hearing Aids Using Earphones Coupled to the Ear by Means of Ear Inserts ......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.