The AES11 standard published by the

Audio Engineering Society The Audio Engineering Society (AES) is a professional body for engineers, scientists, other individuals with an interest or involvement in the professional audio industry. The membership largely comprises engineers developing devices or product ...

provides a systematic approach to the

synchronization Synchronization is the coordination of events to operate a system in unison. For example, the Conductor (music), conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are sa ...

of digital audio signals. AES11 recommends using an

AES3 AES3 is a technical standard, standard for the exchange of digital audio signals between professional audio devices. An AES3 signal can carry two channels of pulse-code modulation, pulse-code-modulated digital audio over several transmission medi ...

signal to distribute audio clocks within a facility. In this application, the connection is referred to as a Digital Audio Reference Signal (DARS). Further recommendations are made concerning the accuracy of sample clocks as embodied in the interface signal and the use of this format as a convenient synchronization reference where signals must be rendered co-timed for digital processing. Synchronism is defined, and limits are given which take account of relevant timing uncertainties encountered in an audio studio.

Related developments

AES11 Annex D (in the November 2005 or later printing or version) shows an example method to provide

isochronous A sequence of events is isochronous if the events occur regularly, or at equal time intervals. The term ''isochronous'' is used in several technical contexts, but usually refers to the primary subject maintaining a constant period or interval ( ...

timing relationships for distributed AES3 structures over asynchronous networks such as

AES47 AES47 is a standard which describes a method for transporting AES3 professional digital audio streams over Asynchronous Transfer Mode (ATM) networks. The Audio Engineering Society (AES) published AES47 in 2002. The method described by AES47 is ...

where reference signals may be locked to common timing sources such as GPS. In addition, the

has now published a related standard called AES53, that specifies how the timing markers already specified in

may be used to associate an absolute time-stamp with individual audio samples. This may be closely associated with AES11 and used to provide a way of aligning streams from disparate sources, including synchronizing audio to video in networked structures. The media profile defined in annex A of AES67 provides a means of using AES11 synchronization via the

Precision Time Protocol The Precision Time Protocol (PTP) is a protocol for clock synchronization throughout a computer network with relatively high precision and therefore ''potentially'' high accuracy. In a local area network (LAN), accuracy can be sub-microsecon ...

References

{{reflist Audio engineering Sound Broadcast engineering Audio Engineering Society standards