MPEG-H and the evolution of broadcast audio

Broadcast audio has of course come a long way since the early days of television. Standardisation of broadcast audio quality began as early as 1941 when the NTSC (National Television System Committee) standard was adopted in the US, which mapped out provisions for monophonic audio.

Programmes were delivered with mono sound until the 1980s when stereo sound was first introduced, bringing a richer and more realistic audio experience. The Multichannel Television Sound (MTS) standard for stereo sound was approved in the US in 1984, and in the UK at around the same time, broadcasters were beginning to use NICAM (Near Instantaneous Audio Multiplex) compression for broadcasting programmes in stereo. Many European countries as well as some countries in the Asia-Pacific region also implemented the NICAM standard to broadcast in stereo.

The transition from analogue to digital broadcasting in the late 1990s and 2000s was another huge development in television broadcasting, significantly improving audio quality and allowing for more sophisticated audio standards. The US and several other countries adopted the ATSC (Advanced Television Systems Committee) standard, while the UK and many other parts of the world adopted DVB (Digital Video Broadcasting) or ISDB (Integrated Services Digital Broadcasting) standards.

Rise of MPEG-H
Next came the development of the MPEG-H group of standards. Developed by the ISO/IEC Moving Picture Experts Group (MPEG) with primary contribution by Fraunhofer IIS in 2014, MPEG-H Audio is a next-generation audio coding standard that provides flexibility, high efficiency, and superior audio quality. Crucially, it was developed to meet the demands of modern audio applications including broadcasting, streaming, mobile playback and immersive audio environments. It’s designed to provide high-quality audio and video experiences across a wide range of devices and applications and includes 3D audio and interactive audio features.

The first standard in the MPEG-H group was published in 2015, and since then, it’s been incorporated into a range of broadcasting standards and consumer devices. It’s included in the newest release of broadcasting standards ATSC (3.0) and DVB and has been used in South Korea since 2017 and Brazil since 2019. The MPEG-H audio system has been selected by the Brazilian SBTVD Forum as the sole mandatory audio codec for its next-generation TV 3.0 standard, expected to launch next year.

An evolving landscape calls for adaptability
A lot has changed in the broadcast industry over recent years and traditional broadcasters are having to adapt to stay competitive as more and more viewers choose to stream content from one of the many streaming services rather than view content on traditional linear TV. Designed to work in streaming applications as well as in traditional broadcast systems, MPEG-H Audio’s adaptability makes it an ideal solution for this continuously evolving broadcast landscape. It supports multi-channel and object-based audio, which gives viewers unprecedented control over different sound elements within a broadcast for a personalised audio experience.

Expectations around broadcast visual and audio quality have never been higher, and MPEG-H Audio’s ability to provide high-quality, immersive, and customisable audio can help broadcasters and streaming services alike meet the demands of modern-day audiences. Unlike conventional audio codecs, which are limited to fixed channels, MPEG-H Audio allows for dynamic spatial audio rendering, to enhance the realism and immersion of audio content. As immersive technologies develop and become more available and affordable, we’ll likely start to see broadcasters and content providers using AR and VR to take video to a whole new level. Having great audio is a critical component of these multi-sensory immersive experiences and MPEG-H Audio’s capabilities will help to create engaging and immersive experiences.

3D audio and personalised experiences
One of the standout features of MPEG-H Audio is that it enables broadcasters to deliver 3D audio effects, enveloping listeners with sound from all directions. This is likely to be particularly impactful with live events such as sports and concerts, where spatial audio can recreate the feeling of being in the middle of the action. Viewers can feel the roar of the crowd or the subtle nuances of a live musical performance as if they were present at the venue. In live concerts, MPEG-H Audio allows for multiple audio perspectives, such as the artist’s on-stage performance, the front-row audience perspective, or a surround sound mix that captures the ambience of the venue. This flexibility enhances the viewer’s connection to the event, making remote experiences more compelling and lifelike.

Additionally, MPEG-H Audio’s capacity for personalised audio experiences also does much to enhance the overall viewing enjoyment. With this capability, listeners can adjust audio elements such as dialogue, music, and effects according to their personal preferences. When viewing a sports event, viewers will be able to choose different commentary objects, adjust crowd noise, or select specific sounds from the field, such as player communications or referee calls.

MPEG-H Audio has already shown its unique capabilities during several major live sporting events and music shows in recent years. In 2018, the EBU delivered the Eurovision Song Contest (ESC) in Lisbon and the European Athletic Championships in Berlin in immersive and personalised sound. It was again used in the live broadcast and streaming service during the ESC’s 2019 edition from Tel Aviv. For the 2019 Rio de Janeiro Carnival and Rock in Rio events, Globo, Latin America’s biggest media network made use of MPEG-H Audio to allow the audience to choose between stage mixes, crowd perspectives or enhance the level of commentary in relation to the background for improved speech intelligibility.

A major milestone for MPEG-H Audio was during the 2022 Football World Cup in Qatar, when Globo started to transmit all matches with immersive sound according to the Brazilian TV 2.5 standard on its commercial free-to-air channels reaching millions of Brazilian households. For the same event, Korea’s broadcasting channel SBS deployed an app that allowed viewers to select between different audio presentations, for example selecting the preferred commentary, changing the level of commentary relative to the background or switching-off the commentary all together.

The next ‘big thing’ in the deployment of MPEG-H Audio is the Olympic Games in Paris, which are being transmitted with immersive and personalised sound in the first next-gen TV production using Brazil’s upcoming TV 3.0 standard.

Future prospects
Many streaming services have already integrated next-gen audio formats such as MPEG-H Audio, Dolby Atmos and Dolby AC-4 to deliver premium audio experiences. Looking ahead, MPEG-H Audio’s role in the future of broadcast audio is primed to expand further as broadcasters leverage its capabilities to create interactive audio events that engage audiences on a deeper level. MPEG-H Audio is set to transform broadcast audio, elevating the viewing occasion through immersive, personalised, and high-quality sound. As broadcasters continue to innovate and adapt, MPEG-H Audio will no doubt shape the future of how we enjoy sound in the digital age. TVBEurope