This standard specifies requirements for audiometric equipment designed for pure tone audiometry in the frequency range from 8000 Hz to 16000 Hz, in addition to those requirements that are applicable and already specified in GB/T 7341.1. The purpose of this standard is to ensure that different types of equipment that comply with this standard give essentially the same results when extended high-frequency audiometry is performed on a given human ear. GB/T 7341.4-1998 Audiometer Part 4: Equipment for extended high-frequency audiometry GB/T7341.4-1998 Standard download decompression password: www.bzxz.net
This standard specifies requirements for audiometric equipment designed for pure tone audiometry in the frequency range from 8000 Hz to 16000 Hz, in addition to those requirements that are applicable and already specified in GB/T 7341.1. The purpose of this standard is to ensure that different types of equipment that comply with this standard give essentially the same results when extended high-frequency audiometry is performed on a given human ear.

GB/T 7341.4—1998
This standard is based on the International Electrotechnical Commission standard IEC645.4:1594 audiometer, part 4, extended high-frequency audiometric equipment.
Since the international standard is mature in technology and widely promoted internationally, it will play a role in promoting the unification of hearing values ​​in my country, so it is adopted in a directional manner to meet the needs of international technical exchanges as soon as possible. GB/T7341 includes the following four parts under the general title of audiometer: Part 1 Pure tone audiometer
Part 2: Speech audiometric equipment
Part 3: Short-duration auditory test signals for audiometry and neuro-otology Part 4 Extended high-frequency audiometric equipment
From the date of implementation of GB/T7341.1—1998 to GB/T7341.4—1998, the original GB7341—87 "Hearing" will be invalidated. This standard is proposed by the National Technical Committee for Standardization of Electroacoustics and Audiovisual Equipment. This standard was prepared by the National Institute of Metrology of China. The drafting unit of this standard is: National Institute of Metrology of China. The main drafters of this standard are Zhang Xuncai, Shuai Zhengping, Gu Jianxiu, Qiu Jianhua and Shen Yang. This standard is entrusted to the National Institute of Metrology for interpretation. GB/T 7341.4—199E
IEC Foreword
1) IEC (International Electrotechnical Commission) is a world-wide standardization organization including all national electrotechnical committees (IEC National Committees). The purpose of IEC is to promote international cooperation on all issues related to standardization in the electrical and electronic fields. For this purpose and other activities, IEC publishes international standards. The work of its formulation is entrusted to the technical committee, and any IEC national committee interested in this is always involved in this "formulation work. International, governmental and non-governmental organizations associated with IEC may also participate in the formulation work. According to the conditions determined between the two organizations, IEC works closely with the International Organization for Standardization (ISO). 2) The formal resolutions or agreements on IEC technical documents formulated by all national committees that pay special attention to this project express the international consensus on the subject involved as much as possible. 3) They are published in the form of standard technical reports or guides in a recommended manner for international use and are accepted by the national committees in this sense.
4) In order to promote international unification, IEC national committees explicitly participate in the adoption of IEC international standards in their national and regional standards. Any differences between IEC standards and corresponding national or regional standards should be clearly stated in the store. International This part of standard TFC645 was prepared by IEC Technical Committee 29, "Electroacoustics", forming the first edition of IEC645-4. The text of this standard is based on the following documents:
29(CO)215
Voting report
29(CO)220
Full information on the approval of this standard can be found in the voting report shown in the table above. Under the general title "Audiometers", IEC645 consists of the following parts:Part 1: Pure tone audiometers
Part 2: Speech audiometry equipment
Part 3: Brief auditory test signals for use in audiometry in otologyPart 4: Equipment for extended high-frequency audiometry
GB/T7341.4—1998
This standard describes equipment designed for hearing measurements in the frequency range from 8 000 Hz to 16 000 Hz. GB/T7341.1 describes the use of pure tone audiometers from 125 1994-03-1998 This standard specifies requirements for pure tone audiometers for use in the frequency range from 8 000 Hz to 8 000 Hz. Many of these requirements are common to both frequency ranges and therefore only those requirements specified specifically for the high frequency range are included in this standard. National Standard of the People's Republic of China
AudiometersPart 4.
Equipnent for extended high-frequency audiometry1 Range
GB/T 7341. 4--1998
idt IEC 645-4:1994
Replaces GB 7341— 8
This standard specifies requirements for pure tone audiometers for use in the frequency range from 8 000 Hz to 8 000 Hz in addition to those requirements that are applicable and already specified in GB/T 7341.1. The purpose of this standard is to ensure that different types of equipment that meet this standard will give essentially the same results when extended frequency audiometry is performed on a given human ear.
2 Referenced Standards
The following standards contain provisions that, through reference in this standard, constitute provisions of this standard. When this standard was published, the following versions were valid. All standards are subject to revision, and parties using this standard should investigate the possibility of using the latest versions of the following standards. GB 3240--82 Frequencies commonly used in acoustic measurements GB4851-81 Standard zero grade for pure tone audiometers GB/T16296-1996 Sound field audiometry using pure tone and narrowband lie detection signals for acoustic audiometry GB/T16403--1996 Methods of acoustic audiometry Basic audiometry for pure tone air conduction and bone conduction valves GB/T 7341.1-1998 Audiometers Part 1: Pure tone audiometers IS0889.7:1996 Standard grades for calibration of acoustic audiometric equipment, Part 7, Standard reading values ​​for listening in white and diffuse field conditions.
3 Definitions
This standard adds the following definitions:
3.1 Extended high-frequency The audiometric frequency range from 8 000 Hz to 16 000 Hz. Note: The frequency 8000 H is used as the highest frequency in the common range and the lowest frequency in the extended high range. 4 Functions of the extended high frequency audiometer
The minimum functional facilities of the extended high frequency audiometer are listed in Table 1. Other functional facilities are not excluded. Table 1 Extended high frequency audiometer minimum functional facilities Functional facilities
Two earphones
Embracing earphones
Mandatory: ×
Optional:
5 General requirements
Functional facilities
Masking-pull noise
Internal circuit
Contralateral earphone
Pure tone switch
Pure tone on/off
Pulse pure tone
Subject response system
Auxiliary electrical signal output
External signal inputbzxZ.net
Signal indicator
Operator's communication with the subject
G/T 7341. 4—1998
Table 1 (end)
Mandatory; x
Optional:○
All requirements not stated in this standard are given in GB/T 7341.1. The following clauses of this standard must be adopted:5.1 Safety requirements
5.2 Subject response system
5.3 Warm-up time
5.4 Power supply changes and environmental conditions
5.6 Testing of dynamic recording and computer-controlled audiometers7.6.3 Rise/fall time of manual audiometers7.6.4 Pulse pure tone 10 for dynamic recording audiometersMarking and instructions for use
6 Test signals
When audiometers are designed to meet the requirements of GB/T 7341.1 and this standard, more stringent requirements should be met at 000 Hz. The test signal shall be a correct tone that meets the following requirements: 6.1 Test signal frequency
The test signal shall be in the range of 8000Hz to 16000Hz: selected from the 1/6 octave interval specified by GB3240. The frequencies with (*) are mandatory frequencies.
*8 000 Hz
9 000 Hz
*10 000 Hz
11 200 Hz
* 12 500 Hz2
11000Hz
*16 000 Hz
Note: IS0/TC4.3/WG1 is currently developing the reference equivalent sound pressure level for frequencies above 8 000 Hz. 6.2
Differential modulation degree.
6.3 Test signal level range for headphones
6.3.1 The minimum hearing level should be -20 dB or lower. GB/T 7341.4--1998
Note: Since the highest frequency hearing level range is very wide among normal hearing subjects, the minimum hearing level of -10 dB is not enough to reach the judgment value for many subjects.
6.3.2 The highest hearing level in the frequency range of 8000Hz~11200Hz should be 90B or higher.50B or higher from 12500Hz to 16000Hz.
Note: The output range of the loudspeaker and bone vibrator is given in the specification. 6.4 Masking sound
6.4.1 All measurements of masking sound shall be made at both ends of the transducer. 6.4.2 The highest masking level shall be 10dB below the highest output level specified in 6.3.2. 6.4.3 The masking sound provided shall be a narrow band of filtered noise with its geometric center near the test frequency. The bandwidth shall be 1/3 and 1/2 octaves, see Table 2. The noise spectral pressure level shall drop by 12dB per octave for at least 3 octaves outside the passband. Thereafter, it will hardly reach more than -36dB relative to the voltage within the passband. Frequency above 31.5kHz is not required to be measured. Table 2 Narrowband Masking Noise: Spectral Density Levels with a Level of 3dB Relative to the Passband Center Frequency High and Low Cutoff Frequency Center Frequency
7 Signal Control
7.1 Masking
Low Cutoff Frequency, Hz
13 450
12 470
High Cutoff Frequency, H
14 030
17 960
Listening level controls shall only use a scale marked in decibels. The listening level shall be varied in steps of 5dB or less. 9510
Note: Standard scales for reference equivalent reading sound pressure levels extending the high frequency range are currently under consideration by ISD/TC48/WG1. Supervisor 1: Explanation, please note! A reference equivalent hearing value should be given and its source should be explained until a standardized value is available. 7.2 Accuracy
The difference between the hearing level produced by the audiometer output transducer and the indicated value at any control level of the test signal level shall not exceed the difference between the output sound pressure level measured between two signal level control levels not exceeding 5dB. It should not differ from the indicated value by more than 3/10 of the range or 1dB. Whichever is smaller:
7.3 Pure tone switch
The pure tone switch shall provide the appearance or blocking of the test pure tone in accordance with the provisions of 7.6 of GB/T7341.1. 7.4 Masking level
The masking level indicator shall have only one scale and a reference zero point, which are common to all frequencies. The masking level should be 5dB or less
8 Unwanted sound
CB/T 7341.41998
The general requirements of 5.5 in GB/T7341.1 should be met for a frequency range extending to 8000Hz16000Hz. In addition to these requirements, it is not necessary for the subject to identify any unwanted sound from the transducer that coincides with the test pure tone even at the maximum setting of the hearing level control.
Note: Many subjects have very good hearing at the low end frequencies, but almost no hearing ability at 14kHz and 16kHz. This fact is not taken into account in CB/T7341.1.
9 Transducer
9.1 Headphones
The reference equivalent threshold sound pressure level will be given in accordance with the headphones specified in GB4854. If other types of headphones are provided, the audiometer manufacturer should provide the reference level and the source and principle of its data. 9.2 Loudspeakers
When loudspeakers are used, the output sound pressure level at the reference point shall be within ±5 dB of the value indicated at 1 m. The test method is specified in GB/T16296. The reference wideband sound pressure level for binaural listening with orthogonal illumination is specified in ISO389-7. If other angles of incidence are provided, the manufacturer shall state the source and principle of the data. 9.3 Bone vibrators
If bone vibrators are provided, the manufacturer shall state the equivalent vibration reading force level and calibration method. 10 Audiogram format
The audiometric symbols shall be the same as those specified in GB/T16403 for the commonly used frequency range. 10.1 Extended high-frequency hearing
When the audiogram is limited to depicting the audiometric results in the extended commercial frequency range, the 1/6 octave division along the frequency axis shall correspond to 10 dB along the hearing axis.
10.2 Combined audiogram
When a drawn audiogram is used to give test results in the range of 125 Hz to 16 000 Hz, the format specified in Chapter 10 of GB/T 16403-1996 should be used.
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