Immersive audio describes an outcome, objective or aspiration achieved by spatial audio content and processes that result in an engaging and immersive experience for the listener, either on its own or in conjunction with other media such as light, video, scenography, odours.

“Immersive audio” is however often used as a convenient way to help relative audio laypersons differentiate between multichannel systems that do spatialisation and more conventional systems that just do stereo or mono.

Beware false prophets: “Immersive” cannot properly be used to describe a device, machine, loudspeaker, screen, light fixture, curtain etc, but often is. Full disclosure – we’re sometimes guilty of it ourselves, where it offers the convenience mentioned above when opening discussions about TiMax. But the trick is to always ascertain exactly what is meant, desired and/or aspired to when the subject of ‘Going Immersive’ comes up.

Spatial audio refers to audio technology that creates a three-dimensional sound environment, simulating the perception of sound coming from various directions, distances, and heights. It aims to replicate the way humans naturally perceive sound in the real world, enhancing immersion and realism in audio experiences. Spatial audio can range from an authentic or accurate representation of a real acoustic panorama, to an enhanced or synthetic soundfield aimed at achieving a more enveloping or “cinematic” creative spatial outcome.

Spatial unmasking is a phenomenon in auditory perception where the ability to detect and understand a sound is improved when it is spatially separated from competing sounds.

In other words, when a target sound is presented from a different direction or location compared to interfering sounds, it becomes easier for the listener to discern and focus on the target sound. This effect is often utilised in spatial audio processing to enhance the intelligibility of desired sounds in environments with background noise or multiple sound sources.

By spatially separating the target sound from interfering sounds, spatial unmasking can improve the overall clarity and perceptual salience of the desired auditory information, leading to a more effective communication and listening experience.

The Haas Precedence Effect, also known as the law of the first wavefront, describes a psychoacoustic phenomenon where the human auditory system perceives a fused sound image when presented with two identical sounds from different directions, and localises to the earliest one provided that the delay between the two sounds is short enough. In such cases, the perceived location of the sound is primarily determined by the direction of the first arriving sound, known as the “lead” or “preceding” sound, while the delayed sound provides the localised amplification, or added loudness.

In immersive spatial audio, the Haas Precedence Effect plays a crucial role in creating a realistic sense of space and directionality. By manipulating the timing and amplitude of audio signals delivered to different channels, audio engineers can simulate the natural panorama of a performance and accurately position sound sources within a three-dimensional space. This technique allows for the creation of lifelike auditory experiences where sounds appear to originate from specific locations around the listener, enhancing immersion and realism.

Source-oriented reinforcement (SOR) is an approach in audio engineering and sound reinforcement where the amplification and processing of audio signals are tailored specifically to localise individual sound sources or sources of interest within a given audio environment. Unlike traditional methods that focus primarily on uniformly reinforcing sound across the entire listening area, source-oriented reinforcement aims to provide localised amplification and processing to optimise the clarity, intelligibility, and impact of specific sound sources.

In source-oriented reinforcement, audio engineers strategically link microphones and speaker systems via delay-matrix signal processing to prioritise localisation of key sound sources, thereby enhancing the perceived clarity and intelligibility of performers on stage, presenters in a conference room or instruments in an orchestra or band. By delivering spatial reinforcement of these critical elements, source-oriented reinforcement helps to ensure that the audience receives the most important auditory information with clarity and precision, even in challenging acoustic environments or amidst competing background noise. This ultimately leads to more engaging and immersive auditory experiences for listeners.

Object-based audio is an audio technology that enables content creators to produce immersive audio experiences by representing sound as discrete audio objects rather than traditional channels. In object-based audio systems, each sound element in a scene—whether it’s dialogue, music, effects, or ambience—is treated as an individual object with its own metadata, including positional information, volume, and other characteristics.

Unlike traditional channel-based audio formats like stereo or surround sound, which require fixed speaker configurations and pre-mixed audio channels, object-based audio provides flexibility and adaptability in sound reproduction. Audio objects can be dynamically positioned within a three-dimensional sound space, allowing for precise localisation and movement of sound sources relative to the listener’s position. TiMax SoundHub is an example of such object-based audio system.

The Image Definition is a particular type of audio object unique to TiMax, as opposed to the familiar coloured blobs we all know that represent input sources such as audio tracks, mics, instruments etc in the likes of Atmos and other spatial platforms, including TiMax.

TiMax lets you scatter Image Definition spatial objects around a space where you want it to make the sound come from – on stage, in surround, overhead, or in special imaging layers for things like reverbs and effects.

At the push of a button TiMax then pre-renders these Image Definitions to apply the correct delay and level parameters to the speakers to make the aforementioned coloured input blobs come from the right places when you place them on or in between them. In simple terms Image Definitions can be thought of as just elaborate output routing objects chosen by you to achieve the spatialisation objectives you want, and which make sure these work for the whole audience.

TiMax can achieve effective localisation and spatialisation with often surprisingly minimal and flexible loudspeaker system topologies. While some other spatial platforms use algorithms that can require quite rigidly defined numbers of speakers, angles and spacings, the flexibility of TiMax Image Definitions means it can create convincing vocal imaging for instance with a simple LCR system, even on a 15-20m wide/deep stage.

Furthermore, where stages and audience areas are challengingly asymmetrical, TiMax can spatially render these with ease. There are often venues, such as for corporate or experiential events, where loudspeakers in non-ideal locations also have to be hidden from view, or the audience area requires coverage from multiple directions. TiMax can handle this no problem, as long as there are at least some speakers pointing from roughly the direction the sound needs to be localised. If in doubt – ask us – we’ve done this stuff before.

As far as the physics is concerned, the answer is yes, because the speed of sound is obviously the same in all directions, so can be used to localise in the z-plane as much as the x and y. In Disney’s Aladdin worldwide franchise a key moment was the flying carpet where you couldn’t see the wires, and TiMax with Tracker were used to make Aladdin and the Princess’s voices come from up in the air.

But the geometry and physiology of our ears sometimes make it harder for us to hear “overhead” due to to shape of the pinna being idealised for horizontal localisation. So with the addition of movement, as in Aladdin, the variable filtering effect actually tells the brain the sound is overhead, effectively by simply changing its EQ.

Good question. There is a volume level limit over which the Haas Precedence stops working and sheer power takes over the imaging. Also high frequency content such as sibilance tends not to delay-image as well; effective Haas Precedence is more of a midrange thing based around the sort of bandwidth occupied by voices and the like.

But we have some tricks to deal with this. Firstly, rolling-off the top-end of vocal mics and/or a dedicated vocal system by 2-3dB lets the engineer get more level on the fader while still getting good localisation.

Where there’s a loud band in the pit, or it’s a large outdoor stage, we add “anchor” speakers upstage or in the set to amplify the “time zero” of the voice, ie making it louder coming off stage, so you can again get a bit more level on the fader to achieve usually 8-10dB of amplification without losing vocal imaging.

If you want to impress people with a bit of jargon, this technique is sometimes rather grandly known as First Wavefront Reinforcement, and it does work remarkably well.