Directional Loudspeaker Arrays for Vehicle Audio Isolation

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Solution Overview

Problem

Existing audio systems in vehicles fail to effectively isolate audio signals for multiple listeners, leading to interference and suboptimal audio quality due to the lack of precise control over directional loudspeaker arrays, especially in complex vehicle environments.

Innovation Solution

The implementation of directional loudspeaker arrays with optimized configurations and signal processing techniques, including the use of multiple acoustic energy sources and microprocessor-driven digital signal processing, to achieve desired radiation patterns and minimize interference between seating positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional loudspeaker systems are used in vehicles, then audio can be played for multiple listeners, but audio signals interfere with each other and audio quality deteriorates due to lack of directional control

Engineering Contradiction:
Improveaudio qualityVSAvoidaudio interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The loudspeaker system is divided into multiple independent loudspeaker elements arranged in arrays, with each element capable of being controlled independently to direct audio signals to specific seating positions, thereby segmenting the audio space and reducing interference between listeners

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the radiation patterns of loudspeaker elements based on detected seating positions and audio selections of individual listeners, allowing real-time optimization of audio delivery to minimize interference and maintain high audio quality for multiple users

Inventive Principle:
Principle #15Dynamics

2Reliability

If directional loudspeaker arrays with multiple elements are implemented, then audio isolation between seating positions is improved, but device complexity increases

Engineering Contradiction:
Improveaudio isolationVSAvoidloudspeaker array configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system incorporates sensors that detect the actual seating positions of listeners and feeds this information back to the control system, which then adjusts the loudspeaker element activation and signal parameters accordingly, enabling adaptive audio isolation without requiring manual configuration

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system automatically determines optimal loudspeaker element configurations based on detected seating positions and listener preferences, eliminating the need for manual setup or complex user configuration while achieving effective audio isolation between seating positions

Inventive Principle:
Principle #25Self-service

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 solution enhances audio isolation between seating positions, ensuring that each listener receives their intended audio source with reduced interference, improving overall audio quality and allowing multiple listeners to enjoy different audio content without disturbance.

Implementation Method 1

over a range of frequencies in which the wavelengths of the radiated acoustic energy are large relative to the spacing of the energy sources with respect to each other, the pressure waves radiated by the acoustic energy sources destructively interfere

Methodology Applied
Scientific EffectAcoustic interference: Interference

Implementation Method 2

radiating acoustic energy corresponding to the audio signals in a desired direction

Methodology Applied
Scientific EffectAcoustic radiation: Sound

Data Source

PatentEP2168397B1System and method for directionally radiating sound
Publication Date: 2020.07.01 BOSE CORP
  • EP2168397B1 patent drawingFigure 1
  • EP2168397B1 patent drawingFigure 2A
  • EP2168397B1 patent drawingFigure 2B

AI summary

An audio system for a vehicle has at least one source of audio signals. A respective directional loudspeaker array is mounted at each seat position and coupled to the at least one source. The at least one source includes a microphone that detects speech from an occupant of the first seat position. Processing circuitry receives signals from the microphone that correspond to the detect speech and drives each second respective loudspeaker array at the other seat positions to radiate acoustic energy corresponding to the detected speech. The processing circuitry processes magnitude and phase of the signals from the microphone to each second directional loudspeaker array so that each second directional loudspeaker array directionally radiates first acoustic energy to the seat position at which the second directional loudspeaker array is located and so that second acoustic energy radiated from the second directional array to the first seat position is less than the first acoustic energy according to a predetermined criteria.