GB/T 4854.8-2007Acoustics -- Reference zero for the calibration of audiometric equipment -- Part 8: Reference equivalent threshold sound pressure levels for pure tone and circumaural earphones (English PDF)

Foreword

GB/T 4854 "acoustic calibration of audiometric equipment - Reference zero" includes eight parts.

--- Part 1. the ear headphones pure tone reference equivalent threshold sound pressure levels (GB/T 4854.1);

--- Part 2. pure tones and insert earphones Reference equivalent threshold sound pressure levels (GB/T 16402);

--- Part 3. pure tones and bone vibrators Reference equivalent threshold force levels (GB/T 4854.3);

--- Part 4. Reference levels for narrow-band masking noise (GB/T 4854.4);

Part --- Article 5. 8kHz ~ 16kHz frequency range of pure tone reference equivalent threshold sound pressure levels (GB/T 4854.5);

--- Part 6. short duration of the test signal reference equivalent threshold sound pressure levels;

--- Part 7. Reference free field and diffuse - field listening hearing threshold (GB/T 4854.7);

--- Part 8. Headphones pure tone reference equivalent threshold sound pressure levels (GB/T 4854.8).

This section GB/T Section 84854 of.

This part identical with ISO 389-8:2004 "Reference zero for the Section 8 acoustic calibrator audiometric equipment. Headphones pure sound base Quasi-equivalent threshold sound pressure levels "(in English).

This section is equivalent to using international standards made editorial changes.

This part of the Annex A, Annex B and Annex C is informative appendix.

This section proposed by the Chinese Academy of Sciences.

The acoustics in part by the National Standardization Technical Committee (SAC/TC17) centralized.

This section is drafted. PLA General Hospital Institution of Otorhinolaryngology, Institute of Acoustics.

Introduction

The enactment of this section, in order to be able to use the same headset 125Hz ~ 16000Hz frequency range for pure tone audiometry. This section it specifies the reference value of 125Hz ~ 8000Hz, GB/T 4854.5 defines the reference value of 8000Hz ~ 16000Hz.

The reference value is based on the most reliable data available laboratories in different countries can be provided at the time determined.

Currently, these reference values only for SENNHEISERHDA200 this kind of model of earphones. This headset for background noise Sound good sound attenuation, and its frequency response in the human ear and ear simulator there is no obvious resonance.

GB/T 4854.8-2007/ISO 389-8:2004 Acoustics - Reference zero for the calibration of audiometric equipment Part 8. Headphones pure tone reference equivalent threshold sound pressure levels

1 Scope

This section provides a frequency range of 125Hz ~ 8000Hz pure tone reference equivalent threshold sound pressure levels (RETSPLs), equipped with a suitable A special type of earphones (SENNHEISERHDA200) of air conduction audiometry calibration equipment.

Note. This paper presents results HDA200 type Headphones Reference equivalent threshold sound pressure levels and test conditions described in Annex A and references.

Appendix B gives the sound attenuation of this ear headphones. Appendix C gives A-E and Class B-E Language audiometer (see

Free field GB/T 7341.2) headphone output equivalent correction value.

2 Normative references

The following documents contain provisions which, through reference to GB/T 4854 to the present, constitute provisions of this section. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

GB/T 4854.1 acoustic calibration of audiometric equipment - Reference zero - Part 1. the ear headphones pure tone reference equivalent threshold sound pressure levels (GB/T 4854.1-2004, ISO 389-1:1998, IDT) Subjective method of measurement of sound attenuation (GB/T 7584.1-2004,. GB/T 7584.1 Hearing protectors - Part 1 ISO 4869-1:1990, IDT) GB/T 7341.2 Audiometers - Part 2. Language audiometric equipment (GB/T 7341.2-1998, idt IEC 60645-2:1993) IEC 60318-1:1998 electric acoustic head and ear simulator - Part 1. Align the ear headphones with ear simulator IEC 60318-2:1998 electric acoustic head and ear simulator - Part 2. Calibration extends the high frequency range audiometer headphones Pro when the acoustic coupling chamber

3 Terms and Definitions

This part of GB/T 4854.1, GB/T 7341.2, GB/T 7584.1 and IEC 60318-1:1998 The terms and definitions.

4 Technical Requirements

Coupled cavity or ear simulator Reference equivalent threshold sound pressure levels and the adapter with the headset model and calibration headphones using. Table 1 to A closed type earphones SENNHEISER HDA200 type with IEC 60318-1:1998 and the provisions of the ear simulator IEC 60318-2:1998 benchmark adapter measured predetermined Figure 1 equivalent threshold sound pressure levels.

GB/T 4854.8-2007/ISO 389-8:2004