Immersive audio: Causing waves

While the exact definition of immersive, spatial or 3D audio might be difficult to agree upon, there is no doubt that it can play a major part in improving sound for a variety of applications. Paul Milligan investigates the technology available.

Audio is an analogue and immersive experience. Emad El Saghir, head of applications at Holoplot, says: “A human being is known to have five senses, one of which is hearing, triggered by sound. Since sound can be perceived from all directions, it contributes to a full immersive experience. Immersive sound therefore is characterised by the psychological perception of being surrounded by foreground as well as background ambient sound sources.

“Our ability to hear in 3D is always the default, since our hearing system will always collect sound energy from all directions.”

The friction lies in the fact that while our ears might be able to hear in 3D, technology might not always be able to reproduce audio in 3D. There is a range of products available in the 3D audio, immersive audio or spatial audio sphere, each one different but created by a feeling of frustration.

Guillaume Le Nost, director of research and development for L-ISA, L-Acoustics says: “L-ISA was started five years ago by the CEO, by his personal frustration with localisation of sound at classical music concerts. The performers would be in the centre of the stage, but if you sat slightly to the left of the stage you would only hear the left speaker, which is not where the performers where.”

Ralf Zuleeg, head of sales services and application engineering at d&b audiotechnik, has a similar tale: “For me it’s a crusade, I’m fed up with stereo. I went to a concert and had a great seat five rows from the front. I was sat in front of the left stack, and I lost all of the magic of the music. We have used all of the effects and compression, it’s time for something else.”

The tech


It’s worthwhile investigating all the products out there in this particular field, but for this article we will be concentrating on five different immersive or spatial audio products in Ambeo from Sennheiser, Soundscape from d&b audiotechnik, L-ISA from L-Acoustics, the offering from Holoplot and Ti- Max from Outboard.

Ambeo is an umbrella term for a range of products from Sennheiser covering the capture or processing or playback of immersive audio. Although launched before the Ambeo brand was established, Sennheiser was already active in this market with the TeamConnect Ceiling microphone. It scans a meeting room to identify the space then uses a sound beam to focus on a specific voice.

The Ambeo VR microphone for 3D sound capture followed next, and the manufacturer now offers a plug-in for professional mixing engineers for streaming platforms so they can mix live sound inputs in 3D for headphone rendering.

Sennheiser also offers the Pro2 headset that uses 3D audio to reduce listener fatigue for call centre employees who have to communicate with people all day long. Coming later this year is an Ambeo soundbar, which although initially aimed at the consumer market, could have applications in virtual meetings rooms, where participants wear headphones.

Veronique Larcher, co-director of Ambeo, explains its potential: “3D sound rendering could be used when you have multiple people in a remote meeting you don’t know that well. You could have them all positioned at different angles so you knew who was speaking and when.”

Soundscape was launched by d&b audiotechnik at ISE 2018 and has three components, the DS100 signal processing engine (with Dante networking and a 64 x 64 matrix) and two software modules. The first module is called En-Scene, an object positional tool that allows individual placement and movement of up to 64 ‘sound objects’. The second, called En-Space, is a room emulation tool to add and modify reverberation signatures for any given space.

L-ISA from L-Acoustics is what the French manufacturer calls an ‘immersive sound art platform’, which combines a 24-channel audio platform and professional loudspeakers with processing hardware and software audio tools. Ti-Max from Out Board is a DSP matrix with playback built-in along with show control capabilities. Because it has a delay matrix built- in users can focus all of the loudspeakers on a particular spot on the stage or on a particular exhibit in a museum. Ti-Max has an audio spatial rendering platform that has two ways of making sound move in a three dimensional way. TimeLine allows users to sequence content in 64 tracks, and apply movement to them by dropping objects, while PanSpace creates pan effects on a virtual representation of the space, which are then automatically dropped by the system into the timeline so they can be sequenced into the show.

Holoplot products use modular Wave Field Synthesis generators in order to shape the sound field in a given environment to deliver immersive audio experiences. Wave Field Synthesis labels a spatial audio reproduction procedure. Unlike other lower-order conventional spatial audio techniques, where localisation relies on the creation of the psycho-acoustical perception of phantom sound sources, Holoplot physically reconstructs the sound field.

El Saghir offers further detail: “For this purpose, the synthesis emulates the wavefronts of the natural source according to Huygens’ principle by creating a virtual source through assembling the elementary waves of a large number of secondary sources (loudspeakers). A computer synthesis independently moves a large number of separately controlled loudspeaker membranes, mostly arranged as a surface array, exactly in that moment, as the wave front of the virtual source would reach its point in space.”

Application experience

Just where do these different vendors see their immersive audio tools being installed? The answer seems to be just about anywhere. Zuleeg says: “The people we are talking to right now are not limited to (market) segments, we are talking to hip-hop bands, we are talking to conference centres, you name it. There are many possibilities, you have the creative and artistic side, you have the immersive side, but my first idea is to improve the situation for the entire audience, give them all a proper perspective of what they hear linked to what they see.”

El Saghir from Holoplot says: “The key applications that we are targeting are corporate events and trade shows aiming at experience and exploring the sound medium as a powerful branding tool. Museums and retail spaces are places where Holoplot technology delivers unique audio experiences to visitors with targeted and immersive sound fields. Theme parks willing to leverage cutting-edge technology as a competitive advantage and to astonish guests through unique realistic 3D sound capabilities. We want to be in challenging acoustic environments, such as public spaces and government buildings, where Holoplot systems provide better control over sound field and thereby avoid reflecting surfaces and deliver highest intelligibility for lower installation costs.”

Dave Haydon, director and co-founder of Out Board, has seen the manufacturer’s solution used in a range of applications in the last four to five years, from cars shows to art galleries to the World Expo in Milan (the Hive exhibit in the UK pavilion) to the Kennedy Space Centre. He says: “People now expect better production standards, we were doing car shows with moving sound ten to twelve years ago, in live performances and theatres. There are whole countries (Denmark, Austria and Switzerland as examples) so used to having localised vocals they won’t do it any other way. For open air shows it can work for intelligibility, in a space for 4,000 to 6,000 people you can make performers sound like the audio is coming from the right place and it makes a huge difference.”

L-Acoustics sees its L-ISA business split between fixed install and touring, and it was in fixed install where it had its first success, at the Puy du Fou historical theme park in France. In the main arena the audience rotates around the stage, and the spatial audio follows the audience in real time as they move.

Alongside visitor attractions, another market with potential is planetariums, with L-Acoustics supplying the audio for the Antarctic Dome at the Coachella and Panorama music festivals in the US. Nost says: “Using immersive sound in a planetarium produces a collective VR experience without headsets and headphones. It is much more enjoyable as you can share the experience but still communicate with others around you. It’s a way to scale VR to the masses.”

Sennheiser partnered with Pink Floyd for its most high profile use of Ambeo technology. Used as part of an exhibition at London’s Victoria & Albert Museum, Ambeo 3D technology delivered 360-degree surround audio of an immersive mix of the song ‘Comfortably Numb’ using 25 loudspeakers.

Demand and supply

Demand for immersive audio solutions in Asia Pacific remains varied. Garry Tjhin, product manager for pro audio solutions at Sennheiser, says: “According to the 2017 statistics, the commercial landscape for immersive content creation had seen an increase in transactions (e.g. research and development investments, sales transactions) over the past years. Scoping in to the relevant sectors for Sennheiser’s 3D audio offerings, the entertainment, gaming and enterprise sectors have witnessed more than 50% growth from the previous year. As far as the Southeast Asia and South Asia regions are concerned, we are confident that the interest in our Ambeo offerings will ride along this trend, especially when (social media) platforms are now ready for viewers to experience content in 360.”

Georg Stummer, product management at d&b audiotechnik, says: “We only launched the product in February but already have three systems installed in very well-known performing arts centres in the APAC region but due to confidentiality agreements we can’t yet talk in any details about these projects. There is great interest in amplifying performances with natural localisation, but also in expanding the acoustic scenery with surround sound, so we are presently designing for a number of live productions and installed applications right across the Asian region.”

Others are looking to enter the APAC market. El Saghir says: “To date, Holoplot does not have any completed installations in Asia but is currently building a distribution network in key regional markets like China and South Korea. In this context, Holoplot will be holding product demos at PalmExpo show in Beijing, China.”

There are many terms for this technology, object-based audio, 360-degree audio, spatial audio, 3D audio, immersive audio, but are some of these vague terms just meaningless marketing buzzwords? Do customers know what they are buying?

The confusion can be used the manufacturer’s advantage says Le Nost: “Having everyone talk about immersive audio is helping the industry. Because the term is still unclear it means we can go in and explain real use cases. We can explain, depending on the sound design aspect, how we can enhance the frontal system or define a surround system or add elevation speakers.”

Haydon explains how they have got the explanation procedure down to a point for customers: “Unfortunately we are all marketeers, and we all have to come up with terms for a concept in order to sell it. 3D audio is an old term that means nothing really.”

Varcher feels the technology will succeed because it has universal appeal: “Immersive audio raises the hairs on your arms, that’s what it provides. 3D or immersive audio is an experience that in itself is universal. There are many technologies to deliver it, depending on the content some are better than others. Is it for 100 people or five people in a room? Are those people moving around? 3D audio requires a Swiss army knife of tools.”

Do any of the vendors feel the AV market, specifically integrators and consultants, fully understand immersive audio yet, or is there still some education needed?

Haydon says: “There is some Luddite-ism in the market, but this is happening right now, and we can make it easy for them, but like in all industries there is some conservatism.”

He has found that because projects are often multi-layered integrators and consultants will outsource any requirement for immersive audio to specialists. A change of mindset is needed says Le Nost: “Usually when you talk to a consultant there is always the notion of what is the specification for a given project. The overall specification is always about the sound pressure levels – will it be loud enough or not loud enough? We are trying to evolve from simple sound metrics such as sound levels to qualitative metrics such as is it going to sound immersive? Is it going to be localised well enough?”

This situation right now might not be ideal, but is improving says Larcher: “Since ISE 2018 I have seen a lot of integrators who want to know more about it. They see it as way to provide additional services to clients and to extend their portfolio.”

Is there any special training needed to handle immersive audio projects? Zuleeg says: “You need training for any kind of new technology. The skillset you need here is to be able to redefine what you want to achieve in your head. You can learn the technical bit, the hardest bit to get your head around is a new way of putting a production together, in terms of positioning. You don’t have to mix the voice right up front anymore, it can be where it should be.”

The introduction of more immersive audio systems is merely a response to wider changes in the market says Le Nost: “The whole industry of sound reinforcement is moving from producing wooden boxes with transducers inside, to becoming a solutions provider where you can meet your customer’s needs. Live sound stages and video displays have grown enormously over the past 20 years, so loudspeakers have been pushed wider apart. It means the sound quality is getting worse, because you are losing the connection between the sound and the face (on stage). The whole point of this kind of new design is to put the sound back as the focus of the show.”

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