GB/T 4854.7-2008
Acoustics.Reference zero for the calibration of audiometric equipment.Part 7:Reference threshold of hearing under free-field and diffuse-field listening conditions (English Version)

Standard No.: GB/T 4854.7-2008
Language: Chinese, Available in English version
Release Date: 2008
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 4854.7-2008
Replace: GB/T 4854.7-1999

Scope: This section specifies the reference hearing thresholds for calibrating audiometric equipment under the following conditions of use. a) The sound field in the absence of the subject, consisting of a free plane traveling wave field (free field) or a diffuse field. Under free-field conditions, the subject should face the sound source (forward incidence). b) Under free field conditions, the acoustic signal should be pure (sine) tone; under diffuse field conditions, it should be 1/3 octave band white noise or pink noise. c) The measurement of the sound pressure level should be carried out at the center of the subject's head (the midpoint of the line connecting the openings of the external auditory canals of the two ears) when the subject is not present. d) Binaural audiometry. Table 1 lists in numerical form the benchmarks of common frequencies from 20Hz to 16kHz and some intermediate listening frequencies up to 18kHz in the 1/3 octave band series specified in GB/T 3240, as shown in Figure 1. It should be emphasized that the hearing threshold benchmark is different from the zero-level audiometry specified in GB 4854.1 and GB/T 16402, because the latter belongs to the single-ear audiometry through headphones, and its sound pressure level is the same as that of the specified coupling cavity and ear simulator. related. Therefore, it is not appropriate to directly compare the benchmarks of this part with GB/T 4854.1 or GB/T 16402.

GB/T 4854.7-2008 Referenced Document

GB/T 16296-1996 Acoustics--Audiometric test methods--Part 2: Sound field audiometry with pure tone and narrow-band test signals
GB/T 16402-1996 Acoustics--Reference equivalent threshold sound pressure levels for pure tones and insert earphones
GB/T 16403-1996 Acoustics--Audiometric test methods--Basic pure tone air and bone conduction threshold audiometry
GB/T 3240 Preferred frequencies for the acoustical measurement
GB/T 4854.1-2004 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 4963-2007 Acoustics.Normal equal-loudness-level contours

2008 GB/T 4854.7-2008 Acoustics.Reference zero for the calibration of audiometric equipment.Part 7:Reference threshold of hearing under free-field and diffuse-field listening conditions
1999 GB/T 4854.7-1999 Acoustics--Reference zero for the calibration of audiometric equipment--Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions