Spatial Audio Frequency Multiplexing for Multiple Sweet Spots

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Solution Overview

Problem

Existing audio systems struggle to effectively render spatial audio for multiple listener sweet spots in environments where speakers are not positioned according to standard layouts, leading to suboptimal audio experiences for different listeners.

Innovation Solution

A method involving frequency domain multiplexing of spatial audio data, where each renderer is associated with a unique listening configuration, allowing for the selection and combination of frequency bands to create optimized loudspeaker feed signals for multiple listener positions and orientations, using filterbanks like STDFT, HCQMF, or QMF to synthesize these signals in the time domain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If spatial audio is rendered for multiple listening configurations simultaneously, then audio quality for multiple listeners is improved, but computational complexity and processing time increase

Engineering Contradiction:
Improveaudio rendering for multiple listening configurationsVSAvoidcomputational processing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The audio frequency spectrum is segmented into multiple frequency bands using filterbanks (e.g., STDFT, HCQMF, QMF). Each renderer processes only specific frequency bands rather than the entire spectrum, dividing the computational task into manageable segments that can be handled independently and then combined.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from time-domain processing to frequency-domain processing by applying filterbanks. This dimensional change allows multiple renderers to operate in parallel on different frequency bands, significantly reducing computational complexity while maintaining the ability to serve multiple listening configurations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If frequency domain multiplexing is used to combine multiple renderer outputs, then computational efficiency is improved, but signal processing complexity increases

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidsignal processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Filterbanks serve as intermediary structures that transform the audio signal into the frequency domain, enabling efficient parallel processing of multiple renderer outputs. The filterbank analysis and synthesis stages act as mediators that manage the complexity of combining multiple frequency-band-specific signals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If each renderer processes the full frequency spectrum, then rendering quality for each configuration is maintained, but processing time and computational load increase

Engineering Contradiction:
Improverendering qualityVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

Each renderer is assigned to process specific frequency bands rather than the entire spectrum. This local quality approach ensures that each renderer focuses on optimizing audio quality for its designated frequency range, maintaining overall rendering quality while reducing individual processing loads and total processing time.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4256809B1Frequency domain multiplexing of spatial audio for multiple listener sweet spots
Publication Date: 2026.01.28 DOLBY LABORATORIES LICENSING CORP
  • EP4256809B1 patent drawingFigure 1
  • EP4256809B1 patent drawingFigure 2A
  • EP4256809B1 patent drawingFigure 2B

AI summary

Some methods involve receiving, by a control system configured for implementing a plurality of Tenderers, audio data and listening configuration data for a plurality of listening configurations, each listening configuration of the plurality of listening configurations corresponding to a listening position and a listening orientation in an audio environment, and rendering, by each Tenderer and according to the listening configuration data, the received audio data to obtain a set of Tenderer- specific loudspeaker feed signals for a corresponding listening configuration. Each Tenderer may be configured to render the audio data for a different listening configuration. Some such methods may involve decomposing each set of renderer-specific loudspeaker feed signals into a Tenderer- specific set of frequency bands and combining the renderer-specific frequency bands of each Tenderer to produce an output set of loudspeaker feed signals. Some such methods may involve outputting the output set of loudspeaker feed signals to a plurality of loudspeakers.