1、C:DOCUMENTS AND SETTINGSQGV33745MY DOCUMENTSDOWNLOADSR-QUE-SG06.55-1994-MSW-E.DOC 22.10.03 15.07.10 QUESTION ITU-R 55/6 Subjective assessment of sound quality in broadcasting using digital techniques (1990-1993-1994) Q. ITU-R 85-2/10 The ITU Radiocommunication Assembly, considering a) that the intro
2、duction of digital techniques in the studio, in transmission circuits and at the transmitter should allow an improvement in quality and more efficient operational use; b) that these techniques entail their own specific signal impairments; c) that it is desirable to ensure high quality performance th
3、roughout the broadcasting chain without unnecessary expense, decides that the following question should be studied 1 What is the relation between subjective assessment and objective measurements for digital systems? 2 What are the tolerable values of subjective impairment in the whole broadcasting c
4、hain? 3 What is the subjective effect of the various studio processes on the digital signal (level changes, frequency response corrections, etc.)? 4 What is the maximum number of times that processing of any kind may be applied to the signal in the studio and the associated subjective effect? 5 What
5、 are the acceptable values of impairment (expressed in objective terms): in recording equipment; in other studio equipment; in broadcasting emissions? NOTE 1 Digital signals used in the studio may differ from those used for transmission. NOTE 2 See in particular Report ITU-R BS.799. NOTE 3 The studi
6、es should also include a comparison with the best analogue techniques. NOTE 4 Close cooperation between Radiocommunication Study Group 6 and Telecommunication Standardization Study Group 9 will be required in this study, further decides 1 that the results of the above studies should be included in (a) Recommendation(s); 2 that the above studies should be completed by 2006. _ - 2 - 6/1-E C:DOCUMENTS AND SETTINGSQGV33745MY DOCUMENTSDOWNLOADSR-QUE-SG06.55-1994-MSW-E.DOC 22.10.03 15.07.10
