Directionally-Controlled Reflections for Headphone Virtualization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating binaural room impulse responses (BRIRs) for headphone virtualization often result in undesired side-effects such as sound coloration and time smearing, as they replicate the acoustical characteristics of physical rooms, which can limit the immersive audio experience across different environments.
Innovation Solution
A method and system for generating directionally-controlled reflections that impart desired perceptual cues to audio signals, using a combination of synthetic room reflections with predetermined directional patterns, such as wobble shapes and diffuse components, to enhance the illusion of a virtual sound source while minimizing audible artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If physical room BRIRs are used to create immersive audio experience, then sense of space is improved, but sound coloration and time smearing occur
Solution Approach 1:
The patent extracts only the desirable perceptual cues (ITD, ILD, IACC, reverberation time, direct-to-reverberant energy ratio) from physical room BRIRs while leaving behind the harmful characteristics (spectral combing, long T60 times, sound coloration). This is achieved by synthesizing BRIRs that incorporate these auditory cues without replicating the full physical room acoustics, thereby separating the useful spatial perception elements from the detrimental sound quality issues.
Solution Approach 2:
The patent applies different quality characteristics to different components of the BRIR. Early reflections are designed with specific directional patterns and temporal characteristics to provide spatial cues, while late reverberation is controlled to avoid excessive T60 times. Each component of the synthesized BRIR is optimized locally to provide desired perceptual effects without introducing harmful artifacts, rather than uniformly replicating entire physical room responses.
2Adaptability or versatility
If physical room BRIRs are used to create immersive audio experience, then sense of space is improved, but time smearing occurs
Solution Approach 1:
The patent extracts the essential spatial temporal cues (early reflection timing, interaural time differences) from physical room measurements while excluding the harmful temporal smearing caused by excessive reverberation tails. The synthesized BRIRs maintain accurate timing information for directional perception while controlling overall reverberation time to prevent temporal smearing of the audio signal.
Solution Approach 2:
The patent employs periodic or structured reflection patterns in the synthesized BRIRs, using controlled sequences of early reflections with specific timing and directional characteristics. This periodic structure provides consistent spatial cues without the random, uncontrolled temporal distribution of reflections found in physical rooms, thereby maintaining spatial perception while avoiding time smearing.
3Adaptability or versatility
If BRIRs with long T60 times are used to enhance externalization, then sense of space is improved, but spectral coloration occurs
Solution Approach 1:
The patent extracts the beneficial externalization cues (interaural cross-correlation, reverberation time characteristics) from long T60 physical room responses while removing the harmful spectral coloration. The synthesized BRIRs incorporate controlled reverberation that provides externalization without the excessive frequency-dependent attenuation and spectral shaping that occurs in real rooms with long reverberation times.
Solution Approach 2:
The patent modifies key parameters of the BRIR synthesis process, specifically controlling reverberation time (T60) to optimal values that provide externalization without coloration. By adjusting parameters such as reflection density, directional distribution, and decay rates in the synthesized BRIRs, the patent achieves externalization effects while maintaining flat frequency response and avoiding spectral coloration inherent in physical rooms with long T60 times.
Data Source
AI summary
The present disclosure relates to reverberation generation for headphone virtualization. A method of generating one or more components of a binaural room impulse response (BRIR) for headphone virtualization is described. In the method, directionally-controlled reflections are generated, wherein directionally-controlled reflections impart a desired perceptual cue to an audio input signal corresponding to a sound source location. Then at least the generated reflections are combined to obtain the one or more components of the BRIR. Corresponding system and computer program products are described as well.