Movable Microphone Configurations for Directional Audio Capture

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Solution Overview

Problem

Existing spatial audio capture technologies, such as binaural and multichannel 5.1 audio, struggle to accurately detect directional sound sources when microphones are not aligned in a horizontal plane, limiting their ability to reproduce sounds from above or below the horizontal plane, and require additional microphones to function in various device orientations.

Innovation Solution

A method that optimizes microphone positions in mobile devices by using movable parts or configurable designs, allowing microphones to adjust their relative positions based on the device's orientation, utilizing directional analysis to determine optimal placements for effective sound source detection and capture, including the use of discrete Fourier transform and sinusoidal windows to analyze frequency domain subbands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If microphones are fixed in a horizontal plane configuration, then binaural and multichannel 5.1 audio capture can be achieved, but the system cannot accurately detect directional sound sources from above or below the horizontal plane

Engineering Contradiction:
Improvedirectional sound source detection accuracyVSAvoiddevice orientation adaptability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements movable microphone assemblies that can dynamically adjust their positions between a first position (e.g., retracted) and a second position (e.g., extended). This dynamic positioning allows the system to optimize microphone geometry for different device orientations, enabling accurate directional sound source detection whether the device is held horizontally or vertically. The movable configuration resolves the contradiction by making the microphone array adaptable rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the spatial parameters of the microphone array by adjusting the relative positions of microphones between different configurations. By modifying the geometric parameters (positions, orientations) of the microphone elements, the system can maintain optimal directional detection capabilities across various device orientations, thereby improving both measurement precision and adaptability simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If additional microphones are added to function in various device orientations, then adaptability improves, but device complexity increases

Engineering Contradiction:
Improvemulti-orientation functionalityVSAvoidmicrophone configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of incorporating multiple fixed microphone arrays for different orientations, the patent uses a dynamic approach where a subset of microphones can be physically repositioned. This allows the same physical microphones to serve multiple functional roles depending on their position, achieving multi-orientation functionality without proportionally increasing the total number of microphones or system complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The movable microphone assemblies serve multiple functions: they can be positioned for optimal performance in both horizontal and vertical device orientations, and can adapt to different audio capture scenarios. This multi-functionality allows the system to achieve versatility without adding dedicated microphone sets for each orientation, thereby avoiding excessive complexity.

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

3Reliability

If microphone positions are adjusted for optimal directional detection, then sound capture quality improves, but the mechanism for adjustment increases device complexity

Engineering Contradiction:
Improveaudio capture qualityVSAvoidmicrophone positioning mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs movable assemblies that allow microphone positions to be adjusted between discrete configurations (first and second positions). These mechanisms are integrated into the device structure and can be actuated based on detected device orientation, providing reliable audio capture quality without requiring overly complex continuous adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2866463B1Multi-channel audio capture in an apparatus with changeable microphone configurations
Publication Date: 2021.04.07 NOKIA TECHNOLOGIES OY
  • EP2866463B1 patent drawingFigure 1A~2A
  • EP2866463B1 patent drawingFigure 2B~3B
  • EP2866463B1 patent drawingFigure 4

AI summary

An apparatus comprises at least one processor, and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: provide an audio capture event wherein one or more microphone configurations are configured to provide one or more audio signals based on at least one acoustic signal from at least one acoustic source, at least one of the one or more microphone configurations being defined by a first position of a first microphone configuration on a first portion and a second position of a second microphone configuration on a second portion, the second portion being movable relative to the first portion.