The Loudness Issue in Todays Audio Systems


Complaints regarding audio being “too loud” have always existed. For example, the change from a television drama with little or no music or sound effects and quiet dialogue to a loud commercial can be quite jarring and will likely cause the viewer to reach for the volume control. This can happen when listening in mono, stereo or surround sound.
The key to resolving this issue is understanding why it happens.
Intensity versus Loudness
Audio is typically measured with VU and Peak Limit meters. VU measures intensity based on the power of the signal. Peak Limit metering measures the intensity of the audio signal in relation to the predetermined minimum/maximum intensity setup of the system.
However, even though one sets VU and Peak Limit metering so that two different programs have the same “levels” on the meters, when listening to the two audio signals back to back, they sound different when it comes to the loudness. This is because there are many factors in how we perceive audio that contribute to the loudness of an audio signal.
Much study continues to be done on how humans hear. Humans typically agree on the audio level of dialogue, but we do not always agree on the other content in an audio program, such as the music and sound effects. Humans do not hear with flat equalization for low-intensity to high-intensity sound — we hear sound with low intensities in the mid frequencies. However, for low and high frequencies, the sound must have a higher intensity for a human to hear it.
There are other factors with regard to how humans hear. For example, when there is a loud sound after a quiet sound, it sounds much louder than if the same loud sound is heard after another loud sound.
Measuring intensity does not tell the whole story for the audio level. Other measurement techniques (LeqA, ITU BS-1770) have been developed that pre-equalize the audio signal to more closely mimic how humans hear. These techniques utilize both audio channels in a stereo signal and the centre channel in a surround sound signal. The audio signal is measured over medium and long periods of time to determine the “loudness” of the audio content. So, in fact, when we measure loudness in a surround sound audio signal (centre channel) using these newer techniques, it is the dialogue loudness level that is being measured.
Dynamic Range
We are now moving to fully digital systems with a much wider audio dynamic range — the range from the quietest sound to the loudest sound. This wider dynamic range provides more creative potential for audio mixes, but can also create more potential for loudness issues.
In analogue systems, there was a narrower dynamic range, and the dialogue level (or the anchor in the audio mix) typically ended up where it should. In an audio mix with a wider dynamic range, the anchor may vary depending on the audio mixers choice; hence, the dialogue level is different between mixes in different programs and commercials.
Therefore, a need exists to normalize the dialogue level. The dialogue normalization level, or dialnorm as it is known, provides a measure of the loudness of the audio signal.
Audio Metadata
Audio metadata is added when the audio is mixed and carried along with the digital audio signal. As long as the audio metadata values (including dialnorm) are correct and the audio metadata always matches the audio if it is changed in any way, downstream audio monitoring devices will react to the audio metadata and help normalize the audio loudness — and help prevent the viewer from reaching for the volume control.
Addressing the Loudness Issue
Having one of the latest loudness measurement devices on the market (based on the latest standard ITU BS1770) will contribute to identifying loudness issues. Histograms provide the means to see a graphical representation of loudness over time, and could possibly even provide a log of loudness over days, weeks and months. Being able to see and update audio metadata is required if one chooses a means of utilizing audio metadata to assist with controlling loudness.
Loudness control devices also can be utilized for unknown content and not utilized for known content. The loudness correction device might require automation system control in determining whether to provide loudness correction and audio metadata updates. Another approach is to utilize a loudness control device that passes audio content when it is correct (dependent on the dialnorm value), and that corrects the loudness to the dialnorm value when required.
Other Considerations
Since audio loudness measurement techniques today are based on dialogue and measurements over a period of time, what about other audio content, such as music and sound effects? For music programming, an anchor point in the audio mix equivalent to dialnorm is utilized. There are issues with audio that is “spiky”—in other words, loud events that are short-term. An example would be an explosion or the loud “crack” of a bat hitting a ball just after the crowd hushes.
There are devices on the market today that take these short-term events into consideration and provide correction.
Conclusion
Using a modern loudness measurement tool based on the latest standard ITU BS1770 will go a long way to assist in analyzing the loudness in audio content. Either correcting the audio to the dialnorm in audio metadata, or correcting the audio content to a dialnorm value in the audio metadata will alleviate the loudness problem.

Tags: iss036 | harris | audio | loudness | dynamic range | audio metadata | complaints | N/A
Contributing Author N/A

Article Copyright tv-bay limited. All trademarks recognised.
Reproduction of the content strictly prohibited without written consent.

Related Interviews
  • Jonathan Harrison interviews Dedo Weigert with the DEDOLIGHT DLED3

    Jonathan Harrison interviews Dedo Weigert with the DEDOLIGHT DLED3

  • Lighting cameraman Jonathan Harrison shows the Celeb and Tegra at IBC 2013

    Lighting cameraman Jonathan Harrison shows the Celeb and Tegra at IBC 2013

  • Jonathan Harrison at BVE North 2012

    Jonathan Harrison at BVE North 2012

  • Jonathan Harrison at BVE North 2011

    Jonathan Harrison at BVE North 2011

  • Root6 at IBC2011

    Root6 at IBC2011

  • Nugen Audio Loudness Meter, Halo Upmix and Halo Downmix at NAB 2018

    Nugen Audio Loudness Meter, Halo Upmix and Halo Downmix at NAB 2018

  • Nugen Audio Loudness Toolkit at BVE 2016

    Nugen Audio Loudness Toolkit at BVE 2016

  • NUGEN Audio: Loudness Toolkit at NAB 2013

    NUGEN Audio: Loudness Toolkit at NAB 2013

  • NUGEN Audio at IBC 2015

    NUGEN Audio at IBC 2015

  • NUGEN Audio at BVE 2015

    NUGEN Audio at BVE 2015

  • Nugen Audio at NAB 2014

    Nugen Audio at NAB 2014

  • NuGen Audio at IBC 2013

    NuGen Audio at IBC 2013

  • Junger Audio at IBC2011

    Junger Audio at IBC2011

  • Glensound show Beatrice the AES67 Network audio intercom beltpack at IBC 2018

    Glensound show Beatrice the AES67 Network audio intercom beltpack at IBC 2018

  • Latest audio product updates from TSL Products at IBC 2018

    Latest audio product updates from TSL Products at IBC 2018

  • 7.1.2 Dolby Atmos support by Halo from Nugen Audio at NAB 2017

    7.1.2 Dolby Atmos support by Halo from Nugen Audio at NAB 2017

  • Nugen Audio at IBC 2016

    Nugen Audio at IBC 2016

  • AudioVideo BrandBuilder Corp at NAB 2016

    AudioVideo BrandBuilder Corp at NAB 2016

  • Nugen Audio at NAB 2016

    Nugen Audio at NAB 2016

  • Minnetonka Audio at NAB 2016

    Minnetonka Audio at NAB 2016

  • Nugen Audio Halo Upmix at BVE 2016

    Nugen Audio Halo Upmix at BVE 2016

  • NOA Audio Solutions at IBC 2015

    NOA Audio Solutions at IBC 2015

  • Audio Network on BroadcastShow LIVE at IBC 2013

    Audio Network on BroadcastShow LIVE at IBC 2013

  • NOA Audio Solutions at IBC 2013

    NOA Audio Solutions at IBC 2013

  • Nugen Audio at IBC 2012

    Nugen Audio at IBC 2012

  • Audio Developments at ProVideo2011

    Audio Developments at ProVideo2011

  • Audio Developments at BVE North 2011

    Audio Developments at BVE North 2011

  • The Telos Alliance at IBC 2016

    The Telos Alliance at IBC 2016

  • Wohler at IBC 2016

    Wohler at IBC 2016

  • RTW at IBC 2014

    RTW at IBC 2014

  • RTW at NAB 2014

    RTW at NAB 2014

  • TSL Products SAM1 MADI at BVE 2014

    TSL Products SAM1 MADI at BVE 2014

  • TSL Products at NAB 2013

    TSL Products at NAB 2013

  • TSL Systems at BVE 2013

    TSL Systems at BVE 2013

  • TSL Products at BVE 2013

    TSL Products at BVE 2013

  • RTW at NAB 2012

    RTW at NAB 2012

  • Emotion Systems at NAB 2012

    Emotion Systems at NAB 2012

  • Triveni Digital at NAB 2012

    Triveni Digital at NAB 2012

  • Qualis at NAB 2012

    Qualis at NAB 2012

  • DK-Technologies at NAB 2012

    DK-Technologies at NAB 2012

  • Sonifex at BVE 2012

    Sonifex at BVE 2012

  • TC Electronic at IBC2011

    TC Electronic at IBC2011

  • RTW at IBC2011

    RTW at IBC2011

  • DK Technology at IBC2011

    DK Technology at IBC2011

  • Linear Acoustic at IBC2011

    Linear Acoustic at IBC2011

  • Nugen Halo Upmix and AMB Updates at IBC 2017

    Nugen Halo Upmix and AMB Updates at IBC 2017

  • Canford at BVE 2017

    Canford at BVE 2017

  • Telos Alliance at BVE 2017

    Telos Alliance at BVE 2017

  • Glensound at IBC 2016

    Glensound at IBC 2016

  • Studer Glacier at IBC 2016

    Studer Glacier at IBC 2016

  • Video Devices PIX-E at IBC 2016

    Video Devices PIX-E at IBC 2016

  • Sound Devices Wingman app at IBC 2016

    Sound Devices Wingman app at IBC 2016

  • Sound Devices 688 at IBC 2015

    Sound Devices 688 at IBC 2015

  • Video Devices PIX-E Series at IBC 2015

    Video Devices PIX-E Series at IBC 2015

  • RTS at BVE 2015

    RTS at BVE 2015

  • Glensound Dante at IBC 2014

    Glensound Dante at IBC 2014

  • NOA Archive Solutions at IBC 2014

    NOA Archive Solutions at IBC 2014

  • Sound Devices at NAB 2014

    Sound Devices at NAB 2014

  • Studio Technologies at NAB 2014

    Studio Technologies at NAB 2014

  • Clear-Com ProGrid at NAB 2014

    Clear-Com ProGrid at NAB 2014

  • Clear-Com HelixNet Partyline at NAB 2014

    Clear-Com HelixNet Partyline at NAB 2014

  • Glensound Atomic Copper at NAB 2014

    Glensound Atomic Copper at NAB 2014

  • Glensound Cub at BVE 2014

    Glensound Cub at BVE 2014

  • Calrec on BroadcastShow LIVE at IBC 2013

    Calrec on BroadcastShow LIVE at IBC 2013

  • Wohler Technologies on BroadcastShow LIVE at IBC 2013

    Wohler Technologies on BroadcastShow LIVE at IBC 2013

  • Nexidia QC on BroadcastShow LIVE at IBC 2013

    Nexidia QC on BroadcastShow LIVE at IBC 2013

  • TSL Products PAM1, SAM1 and PAM PiCo at IBC 2013

    TSL Products PAM1, SAM1 and PAM PiCo at IBC 2013

  • Glensound with the USB Commentary Mixer at IBC 2013

    Glensound with the USB Commentary Mixer at IBC 2013

  • TSL Products at IBC 2013

    TSL Products at IBC 2013

  • Calrec at NAB 2013

    Calrec at NAB 2013

  • Sound Devices at NAB 2013

    Sound Devices at NAB 2013

  • Thear Technology at BVE 2013

    Thear Technology at BVE 2013

  • AC Entertainment Technologies at BVE 2013

    AC Entertainment Technologies at BVE 2013

  • Pinknoise at BVE North 2012

    Pinknoise at BVE North 2012

  • Shure Distribution at BVE North 2012 LIVE Show

    Shure Distribution at BVE North 2012 LIVE Show

  • Sonifex at NAB 2012

    Sonifex at NAB 2012

  • Sound Devices at NAB 2012

    Sound Devices at NAB 2012

  • Clear-Com Eclipse MADI Card at NAB 2012

    Clear-Com Eclipse MADI Card at NAB 2012

  • Glensound at NAB 2012

    Glensound at NAB 2012

  • TSL at NAB 2012

    TSL at NAB 2012

  • Petrol at NAB 2012

    Petrol at NAB 2012

  • Calrec at NAB 2012

    Calrec at NAB 2012

  • Glensound at BVE 2012

    Glensound at BVE 2012

  • Calrec at BVE 2012

    Calrec at BVE 2012

  • DiGiCo at BVE 2012

    DiGiCo at BVE 2012

  • 4HM at BVE 2012

    4HM at BVE 2012

  • Thear Technology Limited at ProVideo2011

    Thear Technology Limited at ProVideo2011

  • 4HM at BVE North 2011

    4HM at BVE North 2011

  • TNP and DSMB at BVE North 2011

    TNP and DSMB at BVE North 2011

  • The Mic Store at BVE North 2011

    The Mic Store at BVE North 2011

  • Sennheiser at BVE North 2011

    Sennheiser at BVE North 2011

  • Source Distribution and Genelec at BVE North 2011

    Source Distribution and Genelec at BVE North 2011

  • HHB and Soundfield at BVE North 2011

    HHB and Soundfield at BVE North 2011

  • Riedel at BVE North 2011

    Riedel at BVE North 2011

  • Solid State Logic at IBC2011

    Solid State Logic at IBC2011

  • Dolby at IBC2011

    Dolby at IBC2011

  • Murraypro at IBC2011

    Murraypro at IBC2011

  • Calrec at IBC2011

    Calrec at IBC2011

  • SADiE at IBC2011

    SADiE at IBC2011

  • Prodys at IBC2011

    Prodys at IBC2011

  • Sound Devices at IBC2011

    Sound Devices at IBC2011

  • NUGEN Loudness Toolkit at NAB 2015

    NUGEN Loudness Toolkit at NAB 2015

  • Cobalt Digital at NAB 2014

    Cobalt Digital at NAB 2014

  • RTW at IBC 2013

    RTW at IBC 2013

  • TSL at BVE 2012

    TSL at BVE 2012

  • Emotion Systems at BVE 2012

    Emotion Systems at BVE 2012

  • HHB and TC Electronic at BVE North2011

    HHB and TC Electronic at BVE North2011

  • Volicon at IBC2011

    Volicon at IBC2011

  • Cobalt Digital at IBC2011

    Cobalt Digital at IBC2011

  • Vision Research at BVE 2013

    Vision Research at BVE 2013


Related Shows
  • The future of audio with BBC R&D at BVE

    The future of audio with BBC R&D at BVE


Articles
AI in Media and Entertainment
David Candler Artificial Intelligence (AI) is a term appearing everywhere these days. What is happening in media and entertainment (M&E) that makes the industry ripe for AI? In other words, why does the M&E industry need AI?
Tags: iss134 | AI | wazee | David Candler
Contributing Author David Candler Click to read or download PDF
An Obituary to Timecode
Bruce Devlin - new A stoic and persistent character that stubbornly refused to change with the times, Timecode has finally passed on, but no-one has noticed. A long-lasting industry veteran, Timecode was brought into this world at an uncertain date in the late 1960s due to the needs of analogue tape workflows and the demand for synchronisation between audio and video devices. A joint activity between SMPTE and the EBU led to the work on Time and Control codes starting its journey to standardisation in the early 1970s.
Tags: iss134 | timecode | smpte | ebu | edit | Bruce Devlin - new
Contributing Author Bruce Devlin - new Click to read
Giving Welsh sport a global audience
Adam Amor From the Ospreys Rugby Union team, to the Football Association of Wales, as well as national cycling, swimming and boxing coverage, Port Talbot based Buffoon Film and Media has been heavily involved in putting Welsh sports on the world stage.
Tags: iss134 | blackmagic | atem | buffoon | micro studio camera | Adam Amor
Contributing Author Adam Amor Click to read or download PDF
Keeping it remotely real
Reuben Such Everyone wants to do more with less. Always have, although it could be argued that doing more with more is something to aspire to, not many have that luxury. So let’s stick with the prevailing winds of doing more with less, and not just doing more, but doing it remotely, particularly in terms of production. Remote production, in particular, is getting a lot of attention in the field these days, but not so much in terms of the remote operation of fixed studios.
Tags: iss134 | remote control | IPE | IDS | Reuben Such
Contributing Author Reuben Such Click to read or download PDF
Accelerated Workflows with eGPU
Mike Griggs From the UK’s National Trust to magazine publishers to manufacturers, digital content creator Mike Griggs has a wide and varied portfolio of clients for whom he creates 3D art, motion graphics and multimedia exhibits. A typical day might involve sampling birdsong near Virginia Woolf’s country estate or creating 3D animations for VR. To keep on top of these demands, Griggs wanted to take the full power of the GPU computing revolution on the road.
Tags: iss134 | sonnet | egpu | amd | post production | editing | Mike Griggs
Contributing Author Mike Griggs Click to read or download PDF