Broadcast Audio Loudness – An in-depth look
SMPTE Toronto / AES Joint Meeting
Topic: BroadcastAudio Loudness – An in-depth look
Date: Tuesday January 10th, 2012
Time: 7:00 PM, (Pizza 6:30PM)
Location: Rogers Communications Centre
Eaton Theatre, Ryerson University (Room RCC-204)
80 Gould Street, Toronto
Arranged By: SMPTE & AES
Sponsor: Evertz Microsystems
With the CALM Act already in place on the US side and the CRTC finalizing regulations for Canada to be implemented this fall, this meeting will help equip you with an understanding of the international standards, recommended practices, the difference and interaction between audio loudness and dynamic range, the various applicable terms/acronyms, how to assess compliance, the effect on the consumer and the technologies available for monitoring, processing and controlling loudness thru the video-food-chain to ensure compliance.
Scott Norcross, Senior Research Engineer, Communications Research Centre, Ottawa
ITU-R BS.1770 and Broadcast Loudness
With the adoption of ITU-R Recommendation BS.1770, Algorithms to measure audio programme loudness and true-peak audio level, there is now an international standard to measure broadcast loudness.
Numerous recommended practices have been published for loudness control that use the ITU-R BS.1770 algorithm as its basis for loudness measurement. Two examples are the ATSC A/85 Techniques for Establishing and Maintaining Audio Loudness for Digital Television and EBU R128 Loudness normalisation and permitted maximum level of audio signals.
This presentation will give an overview of the creation of ITU-R BS.1770 and various activities that led to the adoption of it. Also differences between the ATSC and EBU recommended practices will also be discussed, as well as potential regulations from the CRTC in Canada as well as the CALM act in the US.
Kenneth Hunold, Broadcast Applications Engineer, Dolby Laboratories, Inc., New York
Loudness and Dynamic Range Management within the DTV Audio System
The DTV audio system was designed to individually address loudness management and dynamic range control (DRC.) Audio metadata was included to indicate the loudness of the program and also describe a way to manage artistic variations in dynamic range (when desired or required by the viewer) without permanently altering the content for all viewers. Taken together, these systems were intended to manage loudness first, by indicating how loud a program is so that it can be normalized at reception. Then, by using DRC metadata, the dynamic range of the program can be matched to the “dynamic range” of the listening environment. This dynamic range process using metadata could be “undone” if the viewer has a home theatre or other system where the full dynamic range of the program can be comfortably enjoyed.
The presentation will show loudness variation data on several programming networks and describe strategies for programmers and distribution partners to manage the loudness of the content before delivery. These strategies can be employed cooperatively by producers, distributer, and stations to maintain consistent program loudness.
Because many methods of traditional loudness processing end up reducing the dynamic range of the content, some examples of the interaction between traditional loudness and dynamic range will be demonstrated. Before-an-after charts will be presented, along with some listening examples.
Ron Lynch – Engineering Manager at Technicolor
Broadcast Loudness Topics
In the broadcast and production industries the regulation of allowable sound levels has given rise to a variety of new standards, laws and recommended practices. The relationships between these new terms and the ones directly affecting us will be shown.
Audio measurements from local OTA (over the air) and re-distributed broadcasts will be presented to assess our overall achievements in meeting compliance requirements.
While governments are developing strict rules for the standardization of broadcast audio there appears to be little standardization in the design of the consumer products that receive these signals. For the home viewer the ability to understand and manage the audio metadata arriving at their entertainment systems is not always consistent nor user friendly. Considerations for end user interfaces will be examined.
Jackson Wiegman, Evertz Product Manager - Multiviewer Systems and Intelli Technology
With recent regulations passed around the world, including the CRTC in Canada and the FCC in the United States, regarding the mitigation and management of broadcast audio loudness, broadcasters and multi-channel video programming distributors (MVPD's) are in need of methods to ensure they are compliant within these regulations.
This presentation will give an overview of loudness monitoring and processing technologies that are available to broadcasters and MVPD's to ensure that they are compliant with existing regulations, and also how they can utilize loudness monitoring and processing to provide a better experience to their viewers.
Pizza & Pop Dinner at 6:30pm - Sponsored by Evertz
The SMPTE Board of Managers will meet in room RCC102 starting at 4:45 PM.