<p>Part I Introduction: Sonic Interactions in Virtual Environments: the Egocentric Audio Perspective of the Digital Twin.- Part II Interactive and Immersive Audio: Procedural Modeling of Interactive Sound Sources in Virtual Reality.- Interactive and Immersive Auralization.- System-to-User and User-to-System Adaptations in Binaural Audio.- Audio Quality Assessment for Virtual Reality.- Part III Sonic Interactions: Spatial Design Considerations for Interactive Audio in Virtual Reality.- Embodied and Sonic Interactions in Virtual Environments: Tactics and Examplars.- Supporting Sonic Interaction in Creative, Shared Virtual Environments.- Spatial Audio Mixing in Virtual Reality.- Part IV Sonic Experiences: Audio in Multisensory Interactions: from Experiments to Experiences.- Immersion in Audiovisual Experiences.- Augmenting Sonic Experiences through Haptic Feedback.- From the Lab to the Stage: Practical Considerations on Designing Performances with Immersive Virtual Musical Instruments.- I