Audio Loudness Standards, Recommendations and Guidelines
| Reference ID | Title | Date | Notes |
|---|---|---|---|
| ITU-R BS.1770-5 | Algorithms to measure audio programme loudness and true-peak audio level | November 2023 | Latest in series of standards that define algorithms to measure audio program loudness and true-peak audio level, a method of measuring the Integrated Loudness over entire program segments etc. |
| AES77-2023 | AES Recommended Practice Loudness Guidelines for Internet Audio Streaming and On-Demand Distribution | July 2023 | Comprehensive recommendations based on AESTD1008. |
| ITU-T H.870 – Series H: Audiovisual And Multimedia Systems | E-health multimedia systems, services and applications – Safe listening | June 2022 | Requirements for safe-listening devices and systems (personal/portable audio systems, especially those for playing music) to protect from hearing loss. Glossary and background on sound, hearing and hearing loss. |
| AESTD1008.1.21-9 | Recommendations for Loudness of Internet Audio Streaming and On-Demand Distribution | September 2021 | Latest AES guidelines on Distribution Loudness for streaming, on-demand and voice response systems. Successor to AESTD1004. |
| EBU R 128 S2 | Loudness in Streaming | June 2021 | Supplement to R128 for Streaming |
| EBU R 128 S1 | Loudness Parameters for Short-Form Content | August 2020 | Defines and specifies the values for advertisements, promos etc. |
| EBU R 128 | Loudness Normalisation and Permitted Maximum Level of Audio Signals | August 2020 | The European Broadcasting Union’s primary document for radio and television. Brief, but includes links to 9 EBU and ITU reference documents with details. |
| ANSI/CTA-2075 | Loudness Standard for Over-the-Top Television and Online Video Distribution for Mobile and Fixed Devices | January 2020 | Covers devices, mobile or fixed, that receive OTT and OVD services. It describes management of loudness and dynamic range within a device, with or without the use of metadata. |
| AES71-2018 | Recommended Practice Loudness Guidelines for Over-the-Top Television and Online Video Distribution | July 2018 | Guidelines based on AESTD1006. |
| CENELEC – EN 50332-3:2017 | Sound system equipment: headphones and earphones associated with personal music players – Maximum sound pressure level measurement methodology – Part 3 | 2017 | As the title indicates, this defines SPL measurement of consumer headphones and earphones and European exposure limits to protect hearing. |
| AESTD1005.1.16-09 | September 2016 | Audio Guidelines for Over the Top Television and Video Streaming | Requirements for loudness and true-peak indicating meters |
| AESTD1006.1.17-10 | Loudness Guidelines for OTT and OVD Content | October 2017 | The successor to AESTD1005. Guidelines for audio loudness of online video content, prepared by the AGOTTVS Study Group |
| EBU – Tech 3344 | Practical guidelines for distribution systems in accordance with EBU R 128 | July 2016 | Audio processing and transmission for radio as well as home receivers and video playout equipment |
| EBU – Tech 3341 | Loudness Metering. ‘EBU Mode’ Metering to supplement loudness normalization in accordance with EBU R 128 | January 2016 | Definitions of Integrated, short-term and momentary loudness. Describes ITU’s test signals for testing and calibration of loudness meters and measurement software. |
| EBU – Tech 3342 | Loudness Range: A measure to supplement loudness normalisation in accordance with EBU R 128 | January 2016 | Details on the algorithm, measurement and application of Loudness Range (LRA). |
| EBU – Tech 3343 | Practical guidelines for Production and Implementation in accordance with EBU R 128 | January 2016 | A large paper on strategies for normalization and leveling in production. Surround and stereo downmix corrections are covered, as well as alignment level and listening sound pressure level. |
| ATSC A/85 | ATSC Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television | March 2013 | Guidance to broadcasters and creators of audio for TV content. Developed originally to describe loudness management for ATSC 1.0, it recommends production, distribution, and transmission practices. |
| ITU-R BS.1771-1 | Guidelines for audio loudness of online video content, prepared by the AGOTTVS Study Group | January 2012 | Some requirements for audio metering devices that implement the loudness and true-peak algorithms specified in other ITU-R Recommendations. |
Audio Loudness References
| Title | Author | Date | Notes |
|---|---|---|---|
| AES Loudness Measuring Introduction | C. Gould | October 2024 | Video introduction to loudness measurement for normalization. |
| The Audio Producers Guide to Loudness | R. Byers | August 2021 | Best practices for loudness measurement and normalization in audio storytelling production. |
| Podcasting Basics: Loudness for Podcasts vs. Radio | R. Byers | August 2021 | Discussion of differences in using loudness measurement and normalization in radio and podcast production. |
| Normalized Audio and 0 dBFS+ Exposure | G. Ogonowski | October 2020 | Discussion of audio sample rates and effects near full scale. |
| Using ITU-R BS.1770 to Measure the Loudness of Music versus Dialog-based Content | S. Norcross | October 2020 | Study showing that subjects on average tend to match music content 3-4 dB higher than the speech-based reference signal when measured similar in loudness by ITU-R BS.1770. |
| Adjusting Anchor Loudness | Apple Developer article | 2020 | Paper provides a model to improve accuracy of speech-gated loudness measurement when speech activity is low.) |
| Analyzing Loudness Aspects of 4.2 Million Musical Albums in Search of an Optimal Loudness Target for Music Streaming | E. Grimm | October 2019 | 4.2 million albums were analyzed for loudness aspects such as loudest and softest track loudness. Evidence of development of the loudness war was found |
| Digital Television Audio Loudness Management | J. Starzynski | 2017 | National Association of Broadcasters Engineering Handbook, 11th Ed., pp. 767-790 |
| Standards for safe listening devices: situation analysis | C. Bertin | 2015 | SPL protection limits from WHO and ITU standards. |
| Prevention of Hearing Loss from the Use of Personal Music Players | T. Lund | June 2015 | Test results of SPL from real music players and headphones. Warns that consumers are at risk of hearing damage without limits on exposure. |
| Study of Audio Loudness Range for Consumers in Various Listening Modes and Ambient Noise Levels | J. Kean, E. Sheffield | April 2015 | Investigation of dynamic range desired by listeners in range of environmental noise conditions with speakers and headphones. |
| The End Of The Loudness War? | H. Robjohns | February 2014 (Sound On Sound) | As ITU loudness becomes known, recognized mastering engineer Bob Katz considers the implications for those who make, mix and master music. |
| Audio for Mobile TV, iPad and iPod | T. Lund | 2013 | For five years, the author has systematically studied audio capabilities of Pod and Mobile TV devices… Taking test results and perceptual criteria into account, guidelines are given for optimum station handling of programs for Mobile devices. |
| Difference between the EBU R-128 Meter Recommendation and Human Subjective Loudness Perception | F. Begnert, H. Ekman, J. Berg | October 2011 | Study showing that normalization may yield different perceived loudness between program types. |
| Loudness Descriptors to Characterize Programs and Music Tracks | E. Skovenborg, T. Lund | October 2008 | Loudness range tolerance of listeners: for diagnosing potential problems in ingest material; as a quality check after processing, editing; for use in content delivery. |
| Evaluation of Different Loudness Models with Music and Speech Material | E. Skovenborg, S. Nielsen | October 2004 | Fundamental evaluation of models of loudness perception before ITU BS.1770. |
| Intelligent Program Loudness Measurement and Control: What Satisfies Listeners? | J. Riedmiller, et.al. | October 2003 | Early studies of listener needs for consistent audio loudness in broadcast TV, satellite and cable television services. |
| Comparison of Objective Measures of Loudness Using Audio Program Material | E. Benjamin | October 2002 | Comparison of methods for making objective measurements designed to correlate better with actual loudness (A-weighting, etc.) |
| Speech Levels in Various Noise Environments | K. Persons, et.al | 1977 | Speech Levels in Various Noise Environments |
| The Subjective Loudness of Typical Program Material | Soulodre, et al. | October 2003 | Subjective tests to evaluate the perceived loudness of a broad variety of typical program materials. |
| Objective Measures of Loudness | G. Soulodre, S. Norcross |
October 2003 | Metrics for rating the performance of objective loudness measures are evaluated. |
| Evaluation of Objective Loudness Meters | G. Soulodre | May 2004 | How the ITU-R is investigating objective measures for the perceived loudness of various broadcast program materials. |
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