Peak meters in digital audio systems often register peak sample values rather than true peak levels. Such meters are simple to implement, but they do not always register the true peak value of the audio signal.

Problems occur because the actual peak values of a sampled signal usually fall between sampling instants rather than precisely at a single sampling instant. This results in several peak-sample meter anomalies, including inconsistent peak readings, unexpected overloads, and under-reading and beating of metered tones.

In order to meter the maximum amplitude, or true-peak value, of a sampled signal it is necessary to over sample (or up sample) the signal, essentially using interpolation to increase the sampling frequency of the signal and thus recreating the original signal between the existing samples.

This report discusses criteria for the design of a true-peak meter and proposes appropriate over-sampling ratios to achieve true-peak metering accuracy.

When several digital signals are combined in a mixing desk or other equipment, they must share the same sample timing clock. If all the signals originate within the same studio, it is sufficient to synchronise all the equipment within that studio. With the introduction of transmission of signals in digital form between studios, the problem takes on a new dimension.

This document is intended to provide guidance on synchronisation issues to implementers of systems in which an audio signal originated in digital form in one location is transmitted over a digital network to another location.

Digital management of audio assets – in projects, inventories, collections, libraries, and archives – will increasingly be controlled by metadata; that is, data that describes the audio in some way. Some audio-related metadata already exists in metadata sets developed by other communities, however there is a need within the audio community for more specific and detailed audio metadata.

The question was raised concerning how the upcoming AES metadata standards might be handled in a way that would be consistent across a number of AES documents, and also capable of being harmonised with relevant external metadata sets such as the SMPTE metadata dictionary standards (RP210 metadata elements, RP2009 metadata groups etc.) and the IEC work in the same field.

This report discusses primary issues and outlines some elementary considerations.

This edition revises AES-R6-2005 to complement the latest revision of AES50.

This report is intended to accompany AES50-2005 "High-resolution multi-channel audio interconnection (HRMAI)". It provides additional background, rationale and implementation advice. It should be read in conjunction with AES50-2005. In particular, the first section of this document provides an overview of the technology, which may aid understanding of the context of the standard.

This report covers the concentric connectors known as phone plugs and jacks that are widely used in the audio industry for the interconnection of sound system components as general-use consumer tip-ring-sleeve (TRS) types as well as for the interconnection of broadcast and other professional systems, such as professional TRS types. Because differing dimensions specified by various standards often result in mechanical and, as a consequence, electrical incompatibilities among the various TRS jacks and plugs, this report surveys the standards, connectors, and possible incompatibility problems.

This document is intended to provide background information of use to implementers of AES47, both information on why certain decisions were made and also hints on aspects of the construction of conformant ATM equipment.

The report was revised in 2007 to correspond to the 2006 edition of AES47 and to take account of other events such as the publication of AES51, AES52, and AES53.

This document describes the style for levels standardized in IEC 60027-3, Letter symbols to be used in electrical technology — Part 3: Logarithmic Quantities and Units, and the power and voltage level clauses of IEC 60268-2 Sound system equipment — Part 2: Explanation of general terms and calculation methods, and summarizes and reviews the presently-used notations for expressing levels in condensed or abbreviated form, what expressions are used, and what quantities and reference quantities are implied.

The original document of 1998 was revised 2004-02 to delete considering the adoption of 1 V as the reference quantity for new work in audio engineering.

Three profiles for Precision Time Protocol (PTP) might potentially be used in the professional media environment: the Peer-to-Peer Default PTP Profile of IEEE Std 1588-2008, the Media Profile of AES67 and the SMPTE Profile of SMPTE ST 2059-2. This report compares the profiles and identifies features and parameter ranges that should enable interoperability among equipment conforming to the different profiles.

This report summarizes the AES67 interoperability test event ("plugfest") held at the headquarters of British Broadcasting Corporation (BBC), London on 13 to 16 February 2017. Twenty four companies tested 36 products against each other to confirm interoperability. The results are presented, together with the results of a range of tests of optional operational modes described in the standard.

The synchronization of audio and video (A-V sync, or lip sync) in television continues to pose a problem for producers and broadcasters, because errors in synchronization continue to be a source of audience dissatisfaction.

Although digital television includes timing information that should keep audio and video properly synchronized, this in itself can simply be another source of problems. New display technologies, and separate audio and video signal paths within the living room, present new challenges for lip sync.

Project AES-X177 was started in an effort to help with creating the solution to the problem. It had the aim of standardizing a simple method of measuring lip sync. The task proved more difficult than anticipated and the project was subsequently closed. However this report gathers together two relevant documents that were produced by the British Broadcasting Corporation during the life-time of the project. One is a study of factors that affect perception of lip sync, the other is a study of operational practices in a real broadcast chain.