Audio 3D

Spatial positioning for immersive experiences

Spatial audio makes it possible to place and move sound sources within a three-dimensional space, recreating immersive and realistic environments where position, distance, and direction directly influence perception, allowing highly nuanced spatial control.

Binaural and BinauralDatabase, along with Listener, SpatialAlgorithm, and SpatialAttenuation, form the spatial-audio ecosystem of I/O.

The design scales from a conventional stereo system to a full 3D environment with acoustic simulation, maintaining a balance between accuracy and processing efficiency.

Introduction

I/O uses a single source of truth for the listener, that defines the listening point and its orientation using position (position), forward direction (forward), and vertical axis (up) vectors.

The listener acts as the reference for all spatial calculations, and its parameters —such as the speed of sound or the Doppler factor— can be synchronized dynamically to remain coherent with the acoustic or physical scene, ensuring accurate perception as conditions evolve.

Both the listener and sources use Cartesian coordinates, where the positive Y axis points upward, and magnitudes remain invariant with respect to physical units.

Binaural Modeling

The Binaural node extends the Spatializer behavior by using Head-Related Transfer Functions that precisely model how sound interacts with the shape of the listener’s head and ears to achieve precise and realistic immersive experiences.

This node performs real-time convolution using data provided by the personalized database: BinauralDatabase. The database can be loaded synchronously or asynchronously, enabling progressive initialization in live-rendering audio contexts.

Additionally, Binaural incorporates directivity properties that define a 3D acoustic cone with zones of variable gain, simulating sources that project sound more intensely toward a specific direction improving spatial authenticity for sources with focused emission.

The system also provides control over the attenuation model, which determines how volume decreases as the distance between the source and listener increases.

For deeper insight into the structures, components, and implementation examples, refer to the official documentation, where each concept is covered in greater detail.