Headrest Speaker Spatial Audio Using Trans-Aural and Amplitude Panning

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Solution Overview

Problem

Existing sound processing systems using headrest speakers struggle to provide an enhanced sense of presence by localizing sound images effectively, as they typically focus on localizing virtual sound images on the front side of the listener's head, limiting the immersive experience.

Innovation Solution

A sound processing device that utilizes both headrest and front speakers to achieve a two-step sound image localization process, where a tentative sound image is first localized by headrest speakers in a region excluding the front side and then refined by amplitude panning with front speakers to create a final sound image, enhancing the sense of presence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If only headrest speakers are used to localize sound images, then the system complexity is reduced, but the sense of presence is insufficient

Engineering Contradiction:

Improvesystem complexityVSAvoidsense of presence

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent combines headrest speakers and front speakers into a unified sound processing system. The headrest speakers localize sound images in the rear hemisphere while front speakers handle the front hemisphere, creating a merged spatial audio field that envelops the listener and significantly enhances the sense of presence compared to using headrest speakers alone.

Inventive Principle:

Principle #5Merging (Combining)

2Device complexity

If sound images are localized only on the front side of the head, then the processing is simplified, but the immersive experience is limited

Engineering Contradiction:

Improveprocessing complexityVSAvoidimmersive experience

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent extends sound image localization from the traditional front-side-only approach to a three-dimensional spherical space surrounding the listener's head. By dividing the spatial domain into front and rear hemispheres and assigning different speaker systems to each region, the patent creates a fully immersive 360-degree audio environment that dramatically enhances the immersive experience.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If a two-step localization process is used with both headrest and front speakers, then the sense of presence is improved, but the device complexity increases

Engineering Contradiction:

Improvesense of presenceVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the sound processing function into two distinct processing stages: the first processor handles headrest speaker signals for rear hemisphere localization, and the second processor handles front speaker signals for front hemisphere localization. This segmentation allows each processor to be optimized for its specific function while working together to create a unified immersive audio experience, making the increased complexity manageable and effective.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system improves the sense of presence by supplementing sound from headrest speakers with front speakers, providing a more immersive listening experience by localizing sound images in a novel manner that enhances listener engagement.

Implementation Method 1

the first processor that performs the trans-aural process on the signals corresponding to the plurality of headrest speakers so that a tentative sound image is localized by the plurality of headrest speakers

Methodology Applied

Scientific EffectTrans-aural process:

Implementation Method 2

the second processor that performs the amplitude panning on signals corresponding to the front speakers and a signal processed by the first processor so that a final sound image is localized at a final position between a tentative sound image and the front speakers

Methodology Applied

Scientific EffectAmplitude panning:

Data Source

PatentUS12477295B2Sound processing device, sound system, and sound processing method

Publication Date: 2025.11.18 ALPS ALPINE CO LTD

AI summary

The sound processing device includes the first processor that performs the trans-aural process on the signals corresponding to the plurality of headrest speakers so that a tentative sound image is localized by the plurality of headrest speakers at a tentative position within a region which does not include the front side of the head but includes the left and right sides and the back side of the head, and the second processor that performs the amplitude panning on signals corresponding to the front speakers and a signal processed by the first processor so that a final sound image is localized at a final position between a tentative sound image and the front speakers in accordance with a difference in volume between the tentative sound image and the front speakers.