Report of the meeting of the SC-02-01 Working Group on Digital Audio Measurement Techniques of the SC-02 Subcommittee on Digital Audio, held in Paris, France, 2006-05-21

The meeting was convened by chair S. Harris

The agenda and the report of the previous meeting, 2005-10-08, were accepted as written.

Open Projects

AES-6id-R: Review of AES-6id-2000: AES information document for digital audio - Personal computer audio quality measurements
Harris will send a note to the reflector about the outstanding comments.

The document has stalled since January because the last set of hanging issues were not resolved. The group agreed to move on and publish the document, deferring new issues until the next revision. Since this document is such a substantial improvement on the previous version, the group felt it should be published without unnecessary delay.

Propose to revise the PWD by 2006-06-30, allow 3 weeks for working group comment, then move to PCFC if there are no objections.

AES17-R: Review of AES17-1998 (r2004): AES standard method for digital audio equipment - Measurement of digital audio equipment
A revision is in progress. Several people had signed up at the previous convention to help with this, but there has been no activity. I. Dennis and T. Kite will make an updated PTD by 2006-08-18.

Individuals who would like to contribute to this work should email the reflector with their particular concerns.

Development Projects

AES-X102: Liaison With IEC PT 61606
Project scope: to harmonize digital audio measurement standards through a working relationship between SC-02-01 and IEC TC 100 MT60616 in conjunction with the category-D liaison between AESSC and IEC TC 100.

IEC MT60616 meetings have been scheduled alongside AES standards meetings at AES Conventions. Feedback is being given by members of SC-02-01 on IEC MT60616 drafts.

A committee draft (CD) 61606-3 professional use was distributed on 2006-03-10; the voting draft (CDV) is expected to be issued 2006-06, closing at the end of the year. The next meeting of the IEC 61606-3 project group was held later on the same day as this SC-02-01 meeting.

AES-X118 : ITU-R study group 6 liaison
Project scope: Liaison with ITU-R Working Party 6P, Special Rapporteur Group 3 (6P/SG3)

Status: Continuing liaison to be reviewed following contribution 2005-10 The document about peak metering guidelines has been submitted to ITU; see AES-X141, below.

R. Chalmers reported that the EBU had some concerns about the ITU loudness metering document. He will make the EBU comments available to SC-02-01 for comment.

AES-X151: Specifying jitter performance
Project scope: To establish unambiguous, concise, and useful ways of expressing the jitter performance of audio components and equipment. To find, develop and recommend jitter characterization practices and jitter specification terminologies that will help audio equipment designers and audio system integrators

Thanks to C. Travis for the new version. Harris will send an email indicating 4 weeks available for comments, then PWD will be prepared, to be completed by 2006-08-30.

AES-X141: Accurate measurement and indication of peak signal levels to avoid overload of digital media

Project scope: To report considerations relating to the indication of peak audio signal levels in order to avoid overloading digital media, and to propose a recommended practice. The project does not address issues of subjective loudness; nor does it consider measurements of volume or peak programme level as defined in IEC 60268-17 and IEC 60268-10

A peak metering issues document was written and submitted to ITU.

ITU have included the AES document of 2005-10-10 in their draft measurement standard as an appendix.

We agreed that AES Standards should publish the peak metering document in the form of a report. M. Yonge will format the document to make a report by 2006-06-30. He also suggested that we explore the possibility of publishing this report in the AES Journal, targeting the September 2006 issue. The group agreed with this suggestion.

New Projects

R. Caine raised the possibility of a peak metering information document or standard to complement the work of AES-X141. We decided to wait until the AES-X141 report is published.

New business

There was no new business.

The next meeting will be scheduled in conjunction with the AES 121st Convention in San Francisco, CA., US., 2006-10.