Spherical Microphone Array for Dynamic Binaural Playback

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Solution Overview

Problem

Conventional audio recording and playback methods for VR/AR applications fail to provide a realistic listening experience due to limitations in simulating changing head positions and orientations, leading to an unsatisfactory auditory perception.

Innovation Solution

A system comprising a substantially spherical microphone array and multi-channel processors for recording and playback, capable of processing multiple binaural sound pairs and dynamically reproducing audio based on the user's head position, using a tracking unit to match head coordinates with corresponding microphone pairs for enhanced VR/AR audio experiences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional dummy head with fixed pinnae is used for binaural recording, then the recording structure is simple and fixed, but the listening experience deteriorates when the listener's head position or orientation does not match the dummy head's fixed orientation

Engineering Contradiction:

Improvelistening experienceVSAvoidhead position adaptation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The spherical microphone array is segmented into multiple independently controllable microphone elements distributed across the spherical surface. Each microphone pair can be independently activated to record binaural audio for specific head orientations, allowing the system to segment the continuous space into discrete recording positions that can be selectively combined during playback

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system transitions from a static dummy head to a dynamic spherical microphone array where multiple microphone pairs can be selectively activated based on the listener's actual head position. The playback system dynamically switches between different recorded binaural pairs or interpolates between them to adapt to changing head orientations in real-time

Inventive Principle:

Principle #15Dynamics

2Reliability

If more than two microphones are used for surround sound recording, then the spatial audio coverage is improved, but the playback complexity increases requiring multiple speakers and complex signal processing

Engineering Contradiction:

Improvespatial audio coverageVSAvoidplayback system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system creates multiple copies of binaural audio pairs, each corresponding to a specific head orientation recorded by different microphone pairs on the sphere. Instead of processing all microphones through complex spatial algorithms, the system creates separate binaural copies that can be directly played back through standard headphones, simplifying the playback chain while maintaining spatial accuracy

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The system changes the parameter of microphone configuration from a fixed two-microphone stereo pair to multiple microphone pairs arranged spherically. By varying which microphone pairs are activated based on head position, the system adapts the recording parameters to match the listener's orientation, achieving surround sound coverage without requiring complex multi-speaker playback systems

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If stereo recording with two microphones is used, then the playback setup is simple requiring only two speakers, but the spatial perception and VR/AR listening experience deteriorates

Engineering Contradiction:

Improveplayback setup simplicityVSAvoidspatial perception accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The spherical microphone array serves multiple functions: it can record traditional stereo audio using any two opposite microphones, record binaural audio for specific orientations using paired microphones, or capture full surround sound by activating multiple pairs. This multi-functionality allows the system to maintain playback simplicity while enhancing spatial perception when needed

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system introduces an intermediary processing layer that translates the multi-channel spherical microphone recordings into binaural pairs suitable for headphone playback. This intermediary step converts the complex spatial information into a format that can be delivered through simple two-ear headphones, maintaining ease of operation while improving spatial perception accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11671782B2Multi-channel binaural recording and dynamic playback

Publication Date: 2023.06.06 HUDDLY AS

AI summary

Methods and systems are provided for enhanced audio experiences in VR/AR applications. The apparatuses of this disclosure are adapted to record multiple binaural stereo pairs and play back select binaural pairs corresponding to users' head positions. A substantially spherical microarray is utilized in various embodiments for recording multiple binaural stereo pairs. A VR/AR headset is further adapted to track a user's head positions and dynamically play back binaural sound pairs corresponding to the head positions.