ISO 389-7:2005
Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions

Standard No.

ISO 389-7:2005

Release Date

2005

Published By

International Organization for Standardization (ISO)

Status

Be replaced

Replace By

ISO 389-7:2005/Amd 1:2016

Latest

ISO 389-7:2019

Scope

This section specifies reference hearing thresholds for calibrating audiometric equipment under the following conditions of use. a) The sound field when the subject is not present consists of a free plane traveling wave field (free field) or a diffusion field. Under free field conditions, the subject should face the sound source (shooting forward). b) Under free field conditions, the acoustic signal should be pure (sinusoidal) tone; under diffuse field conditions, it should be 1/3 octave band white noise or pink noise. c) The sound pressure level shall be measured at the center of the subject's head (the midpoint of the line connecting the external auditory canal openings of the two ears) when the subject is not present. d) Binaural audiometry. Note 1: For the hearing threshold correction value caused by the deviation of the selected sound incident angle (45° and 90°) from forward incidence during free-field audiometry, see GB/T 16296. Note 2: For other conditions, see reference [1]. Table 1 lists in numerical form the benchmarks for common frequencies from 20 Hz to 16 kHz and some intermediate listening frequencies up to 18 kHz 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 standard is different from the listening test zero level specified in GB 4854.1 and GB/T 16402, because the latter is a single-ear listening test through headphones, and its sound pressure level is consistent with the specified coupling cavity and ear. Emulator related. Therefore, it is inappropriate to directly compare the benchmarks in this section with GB/T 4854.1 or GB/T 16402.

ISO 389-7:2005 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*， 2007-11-14 Update

ISO 389-7:2005 history

• 2019 ISO 389-7:2019 Acoustics — Reference zero for the calibration of audiometric equipment — Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions
• 2016 ISO 389-7:2005/Amd 1:2016 Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions - Amendment 1: Reference threshold of hearing at 20 Hz and 18000 Hz under free-field l
• 2005 ISO 389-7:2005 Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions
• 1996 ISO 389-7:1996 Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions