Broadcast Loudness

Tired of fielding complaints from viewers about loudness-level inconsistencies between programs and channels of television services?

While obvious to the viewer, these loudness differences have proven difficult to measure with conventional methods and equipment. Take a first step toward solving loudness variations with accurate and consistent measurements. Dolby offers both hardware and software solutions for the measurement of broadcast program loudness, including the Dolby® LM100 Broadcast Loudness Meter hardware product, and the Dolby Media Meter, a new software loudness meter that works on both Mac® and PC platforms. Additionally, the Dolby DP600 Program Optimizer provides the world's first intelligent audio measurement and automated loudness normalization system for file-based broadcast and postproduction environments. 

Dolby LM100 Broadcast Loudness Meter

The Emmy® Award-winning Dolby LM100 Broadcast Loudness Meter 1-U rackmount easily measures the subjective loudness of program dialogue and presents results in a numerical format, eliminating the variations in results among multiple operators interpreting traditional VU or PPM indicators (neither of which are designed to measure loudness).

Applications for the LM100 include network centers, satellite facilities, cable head-end facilities, turnaround uplinks, program ingest facilities, quality control, and postproduction facilities.

The Dolby LM100 Broadcast Loudness Meter features: 

For more Dolby LM100 information:

Watch and listen to a short Flash® introduction to the LM100 Broadcast Loudness Meter for cable, broadcast, postproduction, and DVD authoring applications.

Dolby LM100 spec sheet

Dolby LM100 user's manual 

TV Loudness: Time for a New Approach? 

Intelligent Program Loudness Measurement and Control: What Satisfies Listeners?  

Dolby Media Meter

Dolby Media Meter is a software tool for accurately measuring and logging program loudness for broadcast, packaged media, VOD, and game media. It employs Dialogue Intelligence, coupled with the ITU-R BS.1770-1 algorithm (as used in the DP600 Program Optimizer) to accurately measure loudness as viewers subjectively experience it. Applications for Dolby Media Meter include audio postproduction for broadcast, broadcast quality control, and DVD and Blu-ray Disc™ mastering.

Dolby Media Meter software is available for Mac and Windows® platforms. It is a great solution whether it is used as a stand-alone application or as a plug-in performing either real-time or file-based measurement on audio workstations. It can also be used in conjunction with other Dolby Media Producer products for mastering programs for packaged media.

Dolby Media Meter supports measurement of Dolby Digital, Dolby Digital Plus, Dolby TrueHD, Dolby E, and PCM audio formats. All versions of Dolby Media Meter can analyze with or without using the Dialogue Intelligence feature that automatically detects dialogue in a track and then performs the loudness measurement. Additionally, the software can produce and save log files.

If your facility is looking for a software loudness measurement application, Dolby Media Meter is the cost-effective choice.

Dolby Media Meter Software Installations

Mac/Windows:

Mac OS®:

For more Dolby Media Meter information, see the Dolby Media Meter spec sheet. 

Dolby DP600 Program Optimizer

For file-based broadcast and postproduction environments, the award-winning Dolby DP600 Program Optimizer ensures loudness consistency from program to program, between programs and commercials, or between the channels within your television service. Postproduction, terrestrial networks, affiliates, and cable, satellite, and IPTV operators can equally benefit from the DP600, which intelligently analyzes and automatically normalizes the loudness of programs in standard broadcast file formats. The DP600 automates previously lengthy quality-control processes, and performs them in faster than real time. It intelligently and automatically sets, validates, and corrects the dialogue normalization (dialnorm) metadata parameter without the need for decoding and re-encoding—ensuring a properly encoded bitstream.

The DP600 expands upon Dialogue Intelligence, as used in the Dolby LM100 Broadcast Loudness Meter and Dolby Media Meter, coupled with the ITU-R BS.1770-1 algorithm, to accurately measure loudness as viewers subjectively experience it. It works on many of the most common broadcast media file and audio formats in use today, including Dolby Digital, Dolby Digital Plus, Dolby E, MPEG-1 LII, and LPCM audio formats in any channel configuration. Complete information on the Dolby DP600 Program Optimizer can be found on our Broadcast File-Based Solutions pages, and in the Dolby DP600 spec sheet.

Dolby Volume and Dolby Digital Metadata: An Overall Loudness Solution

Dolby Volume technology performs measurement, analysis, and control of audio loudness levels in consumer equipment using a psychoacoustic model based on the characteristics of human hearing. Dolby Digital (AC-3) is the standard audio system for DTV and HDTV services in ATSC and DVB countries, including digital satellite, cable, terrestrial, and IPTV systems. Dolby Volume complements Dolby Digital in providing an overall solution for controlling loudness over a wide range of consumer media formats.

Dolby Volume addresses loudness variations in program sources other than Dolby Digital, including analog television, gaming, other audio formats used in digital television systems, and additional consumer entertainment media. Dolby Volume maintains system playback volume at the same preferred level across all sources—for example, from a TV, HDTV, or set-top box—or between connected sources such as CD, DVD, Blu-ray Disc players, MP3 players, or games platforms. When Dolby Volume is integrated into a set-top box, television set, or A/V receiver, consumers can set the playback volume once without having to touch the volume control again.

Dolby Digital addresses loudness control through the digital broadcast chain via the use of audio metadata, and specifically the dialnorm parameter. Over 20 audio metadata parameters in Dolby Digital are set during the production of DTV programming and are carried in the audio coding bitstream. Audio metadata parameters maintain the "vision" for the audio created by the program's producer, make life easier for broadcasters, and give viewers the best audio DTV has to offer—whether the viewers own mono, stereo, or 5.1-channel audio systems. For detailed information on audio metadata, see our technical library.

Dolby Digital metadata parameters—specifically the dialnorm parameter—are included in Dolby’s other broadcast audio coding solutions. These include Dolby E, a coding solution designed specifically for the distribution of surround and multichannel audio through digital two-channel postproduction and broadcasting infrastructures. Other broadcast solutions include Dolby Digital Plus and Dolby Pulse—the next-generation audio codecs for broadcast audio transmission to viewers.

The best way for broadcasters to deliver the highest quality audio to their viewers is still through the use of the audio metadata parameters. Accurate setting of the dialnorm parameter in the programming not only affects the reproduced loudness level but also ensures that other metadata parameters included in Dolby audio coding technologies (such as dynamic range control) operate effectively.

As the number of choices in home entertainment increase, potential loudness issues increase as well. The capabilities built into Dolby Digital, as well as Dolby’s other broadcast audio technologies, address these issues within the digital television environment. Hundreds of channels of programming have successfully implemented the dialnorm parameter and are now on-air worldwide, dramatically reducing viewer complaints regarding loudness. With Dolby Volume, we now have an effective solution for the many other sources of entertainment that are available to the consumer today.

For more information on Dolby Volume, see our Broadcast Loudness Issues, The Comprehensive Dolby Approach brochure.

Find more information on Dolby E, Dolby Digital Plus, and Dolby Pulse audio coding solutions.

Dolby Digital or Dolby E Bitstreams for Loudness Control

Once the loudness level of the program's dialogue is measured for surround programming destined for final DTV transmission in Dolby Digital or for distribution in Dolby E, the next step is to set the dialnorm metadata parameter, which indicates the average loudness level of the TV program. Dialnorm is set during program production or in broadcasting facilities to optimize the audio decoding and reproduction at the viewer's location, and it solves viewer complaints about loudness-level inconsistencies between programs or channels of DTV services.

For more information on Dolby Digital and Dolby E metadata, see our technical library. 

For reviews on Dolby technologies and products for broadcast loudness, see the following articles:

Audio Complaints End with Dolby  
TV Technology, October 2005

Working Toward Consistency in Program Loudness
Broadcast Engineering, January 2004

Solving TV Loudness Problems: Can You "Accurately" Hear the Difference?  
Communications Technology, February 2004

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