1、 ; International Telecommunication Union ITU-T P.58TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2013) SERIES P: TERMINALS AND SUBJECTIVE AND OBJECTIVE ASSESSMENT METHODS Objective measuring apparatus Head and torso simulator for telephonometry Recommendation ITU-T P.58 ITU-T P-SERIES RECOMMEN
2、DATIONS TERMINALS AND SUBJECTIVE AND OBJECTIVE ASSESSMENT METHODS Vocabulary and effects of transmission parameters on customer opinion of transmission quality Series P.10 Voice terminal characteristics Series P.30 P.300 Reference systems Series P.40 Objective measuring apparatus Series P.50P.500Obj
3、ective electro-acoustical measurements Series P.60 Measurements related to speech loudness Series P.70 Methods for objective and subjective assessment of speech quality Series P.80 P.800 Audiovisual quality in multimedia services Series P.900 Transmission performance and QoS aspects of IP end-points
4、 Series P.1000 Communications involving vehicles Series P.1100 Models and tools for quality assessment of streamed media Series P.1200 Telemeeting assessment Series P.1300 Statistical analysis, evaluation and reporting guidelines of quality measurements Series P.1400 For further details, please refe
5、r to the list of ITU-T Recommendations. Rec. ITU-T P.58 (05/2013) i Recommendation ITU-T P.58 Head and torso simulator for telephonometry Summary Recommendation ITU-T P.58 specifies the electroacoustic characteristics of the head and torso simulator (HATS) to be used for telephonometric measurements
6、. Both the sound generation and sound pick-up characteristics of this device are specified. This revised Recommendation describes new distortion and output linearity requirements for the artificial mouth of the HATS (as described in Recommendation ITU-T P.51 (1996), and describes the positioning on
7、the HATS of the revised type 3.2 and new type 3.4 artificial ears. The artificial ears described in this Recommendation support super-wideband as well as full-band applications. However, it should be noted that the acoustical impedance of the artificial ears has some limitations in realistically sim
8、ulating human ears. The artificial mouth described in this Recommendation supports super-wideband applications. However, it should be noted that the directionality of the artificial mouth is limited in its ability to simulate the human mouth in the super-wideband frequency range. History Edition Rec
9、ommendation Approval Study Group 1.0 ITU-T P.58 1993-03-12 XII 2.0 ITU-T P.58 1996-08-30 12 2.1 ITU-T P.58 (1996) Erratum 1 2003-01-31 12 2.2 ITU-T P.58 (1996) Erratum 2 2008-07-18 12 3.0 ITU-T P.58 2011-12-14 12 4.0 ITU-T P.58 2013-05-14 12 ii Rec. ITU-T P.58 (05/2013) FOREWORD The International Te
10、lecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and
11、 tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Re
12、commendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Reco
13、mmendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interope
14、rability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that
15、compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, val
16、idity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be require
17、d to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 All rights reserved. No part of this publication may be reproduced,
18、 by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T P.58 (05/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 2 4 Description of the object . 4 5 Physical dimensions of the HATS 4 5.1 Torso . 4 5.2 Head 5 5.3 Pinna . 11 6 Acoustic characteristics
19、 12 6.1 Sound pick-up . 12 6.2 Sound generation 16 6.3 Composite characteristics . 23 7 Miscellaneous . 25 7.1 Calibration of the artificial ears 25 7.2 DRP-ERP transfer function 26 7.3 Stray magnetic field 27 7.4 Atmospheric reference conditions 28 7.5 Markings and calibration fixtures . 28 7.6 Del
20、ivery conditions 28 7.7 Materials . 28 7.8 Stability . 28 Annex A Interpolated 1/12 octave diffuse-field response 29 Bibliography. 30 Rec. ITU-T P.58 (05/2013) 1 Recommendation ITU-T P.58 Head and torso simulator for telephonometry 1 Scope This Recommendation specifies the electroacoustic characteri
21、stics of the head and torso simulator (HATS) for telephonometric use. Both sound emissions and sound pick-up characteristics are specified; the free-field acoustic diffraction is specified as well. The device is intended for airborne acoustic measurements, and is not suitable for measurements that d
22、epend on vibration conduction paths such as bone conduction. The HATS is intended to provide acoustic diffraction similar to that encountered around the median human head and torso, and to generate an acoustic field similar to that generated by the human mouth, both in proximity and in the far field
23、. The methods of use of the HATS in telephonometry are outside the scope of this Recommendation. However, the sound pick-up and diffraction characteristics specified by this Recommendation resemble those recommended by the International Electrotechnical Commission (IEC) for the measurement of hearin
24、g aids. The electroacoustic measurement methodologies for assessing the performance of hearing aids in their telecommunication applications are then, to the extent applicable, specified by the relevant IEC publications. The characteristics of the device are fully specified for narrowband and wideban
25、d speech measurements. Some of its characteristics are described for an enlarged frequency range enabling measurements to be performed for super-wideband speech. Regarding sound pickup, some characteristics are specified up to 20 kHz, thus enabling measurements to be performed for fullband speech as
26、 well. Regarding ear simulator acoustic impedance, characteristics are described in IEC 60318-4 and ITU-T P.57. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of
27、 publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list
28、 of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T O.131 Recommendation ITU-T O.131 (1998), Quantizing distortion measuring equipment using a p
29、seudo-random noise test signal. ITU-T P.50 Recommendation ITU-T P.50 (1999), Artificial voices. ITU-T P.57 Recommendation ITU-T P.57 (1993), Artificial ears. IEC 60318-4 IEC 60318-4 ed1.0:2010, Electroacoustics Simulators of human head and ear Part 4: Occluded-ear simulator for the measurement of ea
30、rphones coupled to the ear by means of ear inserts. IEC 60318-7 IEC 60318-7 ed1.0:2011, Electroacoustics Simulators of human head and ear Part 7: Head and torso simulator for acoustic measurement of hearing aids. ISO 4869-1 ISO Standard 4869-1:1990, Acoustics Hearing protectors Part 1: Subjective me
31、thod for the measurement of sound attenuation. 2 Rec. ITU-T P.58 (05/2013) 3 Definitions For the purposes of this Recommendation, the following definitions apply: 3.1 artificial ear: A device for the calibration of earphones incorporating an acoustic coupler and a calibrated microphone for the measu
32、rement of the sound pressure and having an overall acoustic impedance similar to that of the median adult human ear over a given frequency band. 3.2 axis of rotation: A straight line about which the HATS can be rotated, passing through the HATS reference point (HRP), vertical to the horizontal plane
33、 and lying in the vertical plane. It is vertically oriented when the HATS is in the reference position. 3.3 azimuth angle of sound incidence: The angle between the vertical plane of the HATS and the plane defined by the axis of rotation and the test axis. When the HATS faces the sound source, the az
34、imuth angle of sound incidence is defined as 0. When the right ear of the HATS faces the sound source, the angle is defined as +90. When the left ear of the HATS faces the sound source, the angle is defined as +270. 3.4 diffuse field diffraction at MRP: Difference, in dB, between the third-octave sp
35、ectrum level of the acoustic pressure at the mouth reference point (MRP) and the third-octave spectrum level of the acoustic pressure at the same point in a diffuse sound field with the HATS absent. 3.5 diffuse field frequency response of HATS (sound pick-up): Difference, in dB, between the third-oc
36、tave spectrum level of the acoustic pressure at the ear-drum reference point (DRP) and the third-octave spectrum level of the acoustic pressure at the HATS reference point (HRP) in a diffuse sound field with the HATS absent. 3.6 ear canal entrance point (EEP): A point located at the centre of the ea
37、r canal opening. 3.7 ear canal extension: Cylindrical cavity extending the simulation of the ear canal provided by the occluded-ear simulator out to the concha cavity. 3.8 ear reference point (ERP): A virtual point for geometric reference located at the entrance to the listeners ear, traditionally u
38、sed for calculating telephonometric loudness ratings. 3.9 ear simulator: Device for measuring the output sound pressure of an earphone under well-defined loading conditions in a specified frequency range. It consists essentially of a principal cavity, acoustic load networks, and a calibrated microph
39、one. The location of the microphone is chosen so that the sound pressure at the microphone corresponds approximately to the sound pressure existing at the human ear-drum. 3.10 ear-drum reference point (DRP): A point located at the end of the ear canal, corresponding to the ear-drum position. 3.11 el
40、evation angle of sound incidence: The angle between the reference plane and the test axis. When the vertex points towards the sound source, the elevation angle is defined as +90. When the test axis lies in the reference plane, the elevation angle is defined as 0. 3.12 free-field frequency response o
41、f HATS (sound pick-up): Difference, in dB, between the third-octave spectrum level of the acoustic pressure at the ear-drum reference point (DRP) and the third-octave spectrum level of the acoustic pressure at the HATS reference point (HRP) in a free sound field with the HATS absent (test point). 3.
42、13 free-field plane wave diffraction at MRP: Difference, in dB, between the third-octave spectrum level of the acoustic pressure at the mouth reference point (MRP) and the third-octave spectrum level of the acoustic pressure at the same point in a free sound field with the HATS absent. The character
43、istic is measured for a frontal sound incidence, with a propagation direction parallel to the reference axis. Rec. ITU-T P.58 (05/2013) 3 3.14 HATS reference plane: A plane parallel to the horizontal plane, containing the HATS reference point (HRP). 3.15 HATS reference point (HRP): The point bisecti
44、ng the line joining the ear canal entrance points (EEPs). 3.16 head and torso simulator (HATS) for telephonometry: Manikin extending downward from the top of the head to the waist, designed to simulate the sound pick-up characteristics and the acoustic diffraction produced by a median human adult an
45、d to reproduce the acoustic field generated by the human mouth. 3.17 horizontal plane of HATS: The plane containing the reference axis, perpendicular to the vertical plane. It is horizontally oriented when the HATS is in the reference position. 3.18 lip plane: Outer plane of the lip ring. When the H
46、ATS is in the reference position, the lip plane is vertically oriented. The lip plane of the HATS is normally different from the plane of the mouth simulator orifice. 3.19 lip ring: Circular ring of thin rigid rod, having a diameter of 25 mm and less than 2 mm thick. It shall be constructed of non-m
47、agnetic material and be solidly fixable to the HATS. The lip ring defines both the reference axis of the mouth and the mouth reference point. 3.20 monaural free-field frequency response of HATS (sound pick-up): The difference, in dB, between the third-octave spectrum level of the acoustic pressure a
48、t the ear-drum reference point (DRP) for a given angle of sound incidence and the third-octave spectrum level of the acoustic pressure at the DRP for front (0) sound incidence. 3.21 mouth reference point (MRP): The point on the reference axis, 25 mm in front of the lip plane. 3.22 mouth-ear referenc
49、e plane: Plane containing the ear canal entrance points (EEPs) of both ears and the centre of the lip ring on the lip plane. 3.23 normalized free-field response (sound generation): Difference in dB between the third-octave spectrum level of the signal delivered by the HATS mouth at a given point in the free field and the third-octave spectrum level of the signal delivered simultaneously at the MRP. The characteristic is measured by generating the artificial voice (see ITU-T P.50), a speech shaped random noise, a pink noise or other adequa
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1