Headrest Speaker Arrangement for Diffuse Sound Cloud

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Solution Overview

Problem

Existing vehicle seat audio systems primarily focus on directional audio localization, failing to generate a diffuse sound cloud within the passenger compartment, which limits the immersive audio experience.

Innovation Solution

Integrating at least two inclined speakers in a headrest or speaker box attached to the vehicle seat, with the main sound emission direction angled relative to the backrest, and optionally using a dedicated sound wave reflector on the vehicle ceiling to enhance sound diffusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If speakers are arranged to emit sound directionally for localization, then audio signal localization is improved, but diffuse sound cloud generation deteriorates

Engineering Contradiction:
Improveaudio signal localizationVSAvoiddiffuse sound cloud generation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent transitions from traditional horizontal directional audio localization to a three-dimensional diffuse sound cloud by arranging speakers on multiple surfaces (backrest, seat cushion, headrest) to emit sound waves in various directions, creating a spatial audio environment that envelops the passenger vertically and horizontally rather than directing sound from a single direction

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

Solution Approach 2:

The audio system is divided into multiple independent speaker units distributed across different surfaces and positions within the seat structure. Each speaker unit operates independently to emit sound waves that contribute to the overall diffuse sound cloud, allowing the system to achieve three-dimensional sound distribution through coordinated operation of segmented speaker components

Inventive Principle:
Principle #1Segmentation

2Loss of information

If speakers are positioned for directed surround sound, then localization perception is improved, but immersive diffuse sound perception deteriorates

Engineering Contradiction:
Improvelocalization perceptionVSAvoidimmersive diffuse sound perception
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The system adds vertical dimension to sound emission by placing speakers on the backrest and headrest at elevated positions, creating a three-dimensional sound field that extends from the seat cushion through the backrest to the headrest area, enabling immersive diffuse sound perception that envelops the passenger in all spatial dimensions

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

Solution Approach 2:

Multiple speaker units positioned at different locations and orientations are merged into a unified audio system that works together to create a cohesive diffuse sound cloud. The coordinated operation of speakers on various surfaces combines their individual directional outputs into an integrated three-dimensional sound environment

Inventive Principle:
Principle #5Merging (Combining)

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

This configuration creates a diffuse sound cloud in the passenger compartment, providing a de-correlated and immersive audio experience that is not localized to specific speaker positions, improving sound perception and immersion.

Implementation Method 1

sound waves of the at least two speakers are mixed in a chamber formed by lowered speakers and the side walls in the headrest or speaker box

Methodology Applied
Scientific EffectSound wave mixing: Acoustics

Implementation Method 2

a dedicated sound wave reflector arranged above on a vehicle ceiling

Methodology Applied
Scientific EffectSound wave reflection: Reflection

Data Source

PatentEP3866487B1Vehicle comprising a headrest speaker arrangement
Publication Date: 2024.02.14 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3866487B1 patent drawingFigure 1A
  • EP3866487B1 patent drawingFigure 1B
  • EP3866487B1 patent drawingFigure 1C

AI summary

Disclosed is a vehicle (100) comprising: at least one vehicle seat (18) with a headrest (10) of the vehicle seat (18) or a speaker box (12) to be attached to the vehicle seat (18) or to the headrest (10), the headrest (10) or the speaker box (12) comprising: at least two speakers (20a, 20b) integrated in the headrest (10) or in the speaker (20) box, wherein each of the two speakers (20a, 20b) has a main sound emission direction (25a, 25b), and wherein each of the two speakers (20a, 20b) is fixed in the headrest (10) or in the speaker (20) box in such a way that the respective main sound emission direction (25a, 25b) is inclined with respect to a backrest main direction (30) of a backrest (15) of the vehicle seat (18), wherein the two speakers (20a, 20b) comprise a first speaker (20a) and a second speaker (20b), wherein the first speaker (20a) has a first main sound emission direction (25a) and the second speaker (20b) has a different second main sound emission direction (25b), wherein the first speaker (20a) and the second speaker (20b) are lowered arranged in the headrest (10) or in the speaker box (12) with respect to a sound outlet opening (10c, 12c) at a top side of the headrest (10) or the speaker box (12) so that during operation sound waves (40) emitted from the first speaker (20a) and the second speaker (20b) are mixed in a chamber (9) formed in the headrest or in the speaker box (12); and further comprising a dedicated sound wave reflector (50) arranged above the headrest (10) of the vehicle seat (18) or the speaker box (12) on a vehicle ceiling (45), wherein the sound wave reflector (50) is configured to reflect sound waves (40a, 40b) emitted from the first speaker (20a) and the second speaker (20b) integrated in the headrest or in the speaker box (12) with a lower sound wave loss than the vehicle ceiling (45) in the vehicle (100).