IEEE-661-1979-R2008.pdf
《IEEE-661-1979-R2008.pdf》由会员分享,可在线阅读,更多相关《IEEE-661-1979-R2008.pdf(20页珍藏版)》请在三一文库上搜索。
1、Copyright 1998 IEEE All Rights Reserved1 ANSI/IEEE Std 661-1979 (R2008) An American National Standard IEEE Standard Method for Determining Objective Loudness Ratings of Telephone Connections Sponsor Transmission Systems Committee of the IEEE Communications Society Reaffirmed September 25, 2008 Appro
2、ved June 16, 1978 IEEE Standards Board Approved February 15, 1983 American National Standards Institute Copyright 1979 by The Institute of Electrical and Electronics Engineers, Inc 345 East 47th Street, New York, NY 10017, USA No part of this publication may be reproduced in any form, in an electron
3、ic retrieval system or otherwise, without the prior written permission of the publisher. Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on February 17, 2009 at 15:45 from IEEE Xplore. Restrictions apply. Copyright The Institute of Electrical and Electronics Engineers, Inc. Pro
4、vided by IHS under license with IEEELicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 22:52:54 MDTNo reproduction or networking permitted without license from IHS -,-,- Joseph L. Koepfinger, Chairman William E. Andrus C. N. Berglund Edward J. Cohen Warren H. Cook David B. Dobson R. 0. Dun
5、can Charles W. Flint Approved June 16,1978 IEEE Standards Board Ivan G. Easton, Secretary Jay Forster Ralph I. Hauser Loering M. Johnson Irving Kolodny William R. Kruesi Thomas J. Martin John E. May Irvin N. Howell, Jr, Vice Chairman Donald T. Michael Voss A. Moore William S. Morgan Robert L. Pritch
6、ard Blair A. Rowley Ralph M. Showers B. W. Whittington I Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on February 17, 2009 at 15:45 from IEEE Xplore. Restrictions apply. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with
7、IEEELicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 22:52:54 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword (This Foreword is not a part of IEEE Std 661-1979, Standard Method for Determining Objective Loudness Ratings of Telephone Connections.) . This
8、 IEEE Standard Method for Determining Objective Loudness Ratings of Telephone Connec- tions has been prepared in response to a need by the telecommunications industry for a standard method of testing transmission performance of partial and overall telephone connections in a man- ner that reflects th
9、e attribute of subjective loudness. This document complements and is dependent on IEEE Std 269-1971, Standard Method for Measuring Transmission Performance of Telephone Sets. Individuals from private and government design, manufacturing, and research organizations have given freely of their time in
10、preparing, testing, and reviewing this standard. The IEEE will maintain t h i s document current with the state of the technology. Comments, suggestions, and requests for interpretations should be addressed to: Secretary JEEE Standards Board Institute of Electrical and Electronics Engineers 345 East
11、 47th Street New York, New York 10017 This standard was prepared by the Subcommittee on Telephone Instrument Testing of the Transmission Systems Committee of the IEEE Communications Society. The members of the subcommittee are: K. Simonson, Chairman E. S. Hineline, Jr, Secretary F. T. Andrews L. A.
12、Berry C. F. Buster, Jr M. Chytil J. F. Dunlap J. B. Eppes R. P. Farrell R. F. Foster A. S. Howell J. J. Jetzt B. Katz M. J. Leach G. A. Ledbetter T. Lisbon N. G. Long R. P. McCabe A. Mankivsky D. J. Morgen L. Poradowski L. A. Strommen J. L. Sullivan C. G. Svala . cp s Authorized licensed use limited
13、 to: IHS Stephanie Dejesus. Downloaded on February 17, 2009 at 15:45 from IEEE Xplore. Restrictions apply. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 22:52:54 MDTNo reproduc
14、tion or networking permitted without license from IHS -,-,- SECTION Contents PAGE 1 . Introduction . 5 2 . ScopeandPurpose . 6 3 . Definitions . 6 3.2 Reference System . 6 3.1 LoudnessRating 6 3.3 Objective Loudness Rating (OLR) . 7 3.4 Voltage and Pressure Levels 7 3.5 Overall Objective Loudness Ra
15、ting (OOLR) . 7 3.7 Receiving Objective Loudness Rating (ROLR) . 7 3.10 Source/Load Impedance 7 3.11 LoudnessEquation 7 3.6 Transmitting Objective Loudness Rating (TOLR) . 7 3.8 Sidetone Objective Loudness Rating (SOLR) 7 3.9 Electrical Objective Loudness Rating (EOLR) 7 4 . References 8 5 . Instrum
16、ental Method 8 5.1 General . 8 5.2 Test Equipment . 8 5.3 Meamringsystem . 10 5.4 Calibration 13 5.5 Testprocedure . 13 6 . Computational Method 14 FIGURES Fig 1 H-Pad Circuit . 10 Fig 2 Sending End of Measuring System . 11 Fig 3 Receiving End of Measuring System . 11 Fig 4 A-Measurement of Overall
17、Objective Loudness Rating (OOLR); B-Measurement of Transmitting Objective Loudness Rating (TOLR); C-Measurement of Receiving Objective Loudness Rating (ROLR) ; D-Measurement of Sidetone Objective Loudness Rating (SOLR); . E-Measurement of Electrical Objective Loudness Rating (EOLR); 12-13 Fig 6 Grap
18、hical Loudness Computation Form 15 TABLES Table 1 Table 2 Example of Computation of Transmitting Objective Loudness Rating . Example of Computation of Receiving Objective Loudness Rating 16 16 APPENDIXES Appendix A Loudness Rating Method . 17 Appendix B Weighted Acoustic Source Signal 19 Appendix C
19、Weighted Electrical Source Signal . 20 APPENDIX FIGURES Fig A1 Computation of Speech Loudness . 17 Fig B1 Sound Pressure Spectrum of Continuous Speech at Two Inches from the Lips of aTalker . 19 Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on February 17, 2009 at 15:45 from
20、IEEE Xplore. Restrictions apply. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=HP Monitoring/1111111164 Not for Resale, 04/07/2009 22:52:54 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE Standard
21、Method for Determining Objective Loudness Ratings of Telephone Connections 1. Introduction The methods that are used to measure the transmission performance of telephone connec- tions may be divided into two classes: objective methods and subjective methods. This standard considers an objective meth
22、od that can be used for measuring telephone connections in a man- ner that reflects the subjective attribute of loud- ness with an accuracy suitable for most tele- phone transmission engineering problems. The performance measure is expressed in terms of a defined reference and is referred to as an o
23、bjec- tive loudness rating. The objective method utilizes a sound source to activate the telephone transmitter, and an acoustic coupler and associated microphone (artificial ear) as an acoustic termination for the telephone receiver. The sound source con- sists of a source of electric energy, a spec
24、ial type of loudspeaker unit (artificial mouth), and such supplementary electric and acous- tic components a s may be required so that the ensemble provides a controlled sound field. The artificial mouth and artificial ear provide a simpler means of measuring characteristics of telephone connections
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- IEEE 661 1979 R2008
链接地址:https://www.31doc.com/p-3771040.html