Vehicle Headrest Loudspeaker Layout for Seat-Specific 3D Audio

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Solution Overview

Problem

Providing a satisfying 3D surround sound experience for all passengers in a vehicle is challenging due to the need for precise integration of speakers that consider individual passenger positions and ear anatomy, ensuring optimal sound propagation and minimizing interference between seats.

Innovation Solution

An audio system with four loudspeakers strategically positioned in a vehicle headrest, each emitting sound from specific angles relative to a passenger's ears (above and below, left and right) to create a personalized 3D surround sound experience, with the speakers integrated into the headrest enclosures and directed towards the front of the vehicle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If speakers are integrated into the vehicle interior, then the audio system can be provided, but it is difficult to provide a satisfying 3D surround sound experience for each passenger

Engineering Contradiction:
Improve3D surround sound experienceVSAvoidspeaker integration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by positioning speakers not only horizontally but also vertically relative to the passenger's ears. Four speakers are arranged in a three-dimensional configuration: two speakers positioned above the ears (one left, one right) and two speakers positioned below the ears (one left, one right). This vertical dimension addition creates a true 3D surround sound experience that cannot be achieved with traditional horizontal-only speaker arrangements, directly resolving the contradiction between providing adaptability for 3D sound and managing integration complexity.

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

Solution Approach 2:

The patent applies local quality by customizing the speaker arrangement specifically for each passenger's head position and ear location. The speakers are positioned relative to the passenger's anatomy (above/below left/right ears) rather than using a fixed vehicle-coordinate system. This allows the audio system to adapt to individual passengers regardless of their seating position, providing personalized 3D surround sound while managing complexity through standardized positioning rules.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If speakers are positioned to provide 3D surround sound, then listening experience is improved, but precise integration considering individual passenger positions and ear anatomy is required

Engineering Contradiction:
Improvepersonalized listening experienceVSAvoidspeaker positioning precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies universality by designing a speaker arrangement that serves multiple passengers with different seating positions and anatomical variations. The standardized configuration of four speakers (above-left, above-right, below-left, below-right relative to ear position) can accommodate any passenger in the seat, eliminating the need for custom positioning for each individual. This universal approach maintains personalized listening experience while reducing manufacturing precision requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies preliminary action by pre-positioning the speakers in fixed locations within the headrest structure before the passenger sits down. The speakers are arranged in advance relative to where the passenger's ears will be positioned, rather than adjusting positions based on individual measurements. This preliminary configuration enables personalized 3D surround sound while avoiding complex real-time adjustments or high-precision custom installation.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If four loudspeakers are arranged in the headrest, then 3D surround sound is achieved, but the integration into vehicle interior becomes more challenging

Engineering Contradiction:
Improvesurround sound capabilityVSAvoidspeaker integration ease
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies merging by integrating the four speakers into the headrest structure, combining the audio system with an existing vehicle interior component. Rather than adding four separate speaker units to the vehicle interior, they are merged into the headrest assembly, which simplifies installation and utilizes the headrest's existing mounting structure. This merging approach achieves 3D surround sound capability while improving ease of manufacture and integration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies the nested doll principle by placing the four speakers within the headrest enclosure. The speakers are nested inside the existing headrest structure, utilizing its internal space and mounting capabilities. This nesting approach allows complex speaker integration without increasing overall vehicle interior complexity, as the speakers are contained within an existing component boundary.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 effectively provides a satisfactory 3D listening experience for each passenger by positioning loudspeakers to simulate audio from directly behind their ears, optimizing surround sound and minimizing interference between seats, while allowing for adjustment to accommodate varying ear spacings and headrest configurations.

Implementation Method 1

each of the first, second, third, and fourth loudspeaker receives the audio signals from the audio unit and is configured to reproduce the audio signals

Methodology Applied
Scientific EffectElectroacoustic transduction:

Data Source

PatentEP4478740A1Audio system arranged in a listening environment in a vehicle and headrest for a vehicle
Publication Date: 2024.12.18 HARMAN BECKER AUTOMOTIVE SYST GMBH
  • EP4478740A1 patent drawingFigure 1~2B
  • EP4478740A1 patent drawingFigure 2C~3
  • EP4478740A1 patent drawing

AI summary

An audio system arranged in a listening environment in a vehicle (10) comprises an audio unit (50) configured to output audio signals, a first loudspeaker (402a) arranged in a first headrest (202) of the vehicle (10), a second loudspeaker (402b) arranged in the first headrest (202), a third loudspeaker (404a) arranged in the first headrest (202), and a fourth loudspeaker (404b) arranged in the first headrest (202), wherein each of the first, second, third, and fourth loudspeaker (402a, 402b, 404a, 404b) receives the audio signals from the audio unit (50) and is configured to reproduce the audio signals, the first loudspeaker (402a) is arranged in a position that, when a passenger (30) is seated in front of the headrest (202), is located towards a right side of the passenger's head, and above the passenger's right ear, the second loudspeaker (402b) is arranged in a position that, when a passenger (30) is seated in front of the headrest (202), is located towards a left side of the passenger's head, and above the passenger's left ear, the third loudspeaker (404a) is arranged in a position that, when a passenger (30) is seated in front of the headrest (202), is located towards a right side of the passenger's head, and below the passenger's right ear, and the fourth loudspeaker (404b) is arranged in a position that, when a passenger (30) is seated in front of the headrest (202), is located towards a left side of the passenger's head, and below the passenger's left ear.