Perceptual implications of different Ambisonics-based methods for binaural reverberation

Area of Science:

• Acoustics
• Signal Processing
• Virtual Reality Audio

Background:

• Realistic auralisation of enclosed spaces relies on reverberation.
• High-fidelity rendering is computationally expensive, necessitating simplified models.
• Ambisonics methods offer efficient spatial resolution for reverberant sound fields.

Purpose of the Study:

• To explore the perceptual impact of two efficiency-enhancing simplifications for Ambisonics-based binaural reverberation.
• To evaluate a hybrid Ambisonics approach and the Reverberant Virtual Loudspeaker (RVL) method.

Main Methods:

• Hybrid Ambisonics: Direct sound convolved with dense head-related impulse responses, separate from reverberation.
• Reverberant Virtual Loudspeaker (RVL): Computationally efficient dynamic binaural reverberation for multiple sources.
• Numerical and perceptual evaluations of auralisations for two measured rooms.

Main Results:

• Perceived quality of hybrid Ambisonics auralisations plateaued beyond the third order, a lower threshold than previously reported.
• RVL demonstrated comparable perceived quality to standard Ambisonics renderings.
• The direct sound path processing impacts the optimal Ambisonics order for perceived quality.

Conclusions:

• Hybrid Ambisonics and RVL are effective methods for computationally efficient binaural reverberation.
• These methods maintain high perceived quality in auralisations of enclosed spaces.
• Findings suggest optimized Ambisonics orders and efficient rendering techniques for virtual acoustics.