Rotatable Microphone Array for Adaptive Sound Collection

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Solution Overview

Problem

Conventional voice conference apparatuses cannot effectively collect sound from specific directions, leading to audio feedback and echo issues due to inability to control sound collection directivity.

Innovation Solution

A sound processing apparatus with rotatable sub-housings and microphone arrays that allows for adjustable sound collection range and directivity, incorporating phase control to suppress speaker emissions and reduce echo canceller load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If microphones are provided on four corners of the housing to collect sound from the entire periphery, then sound collection coverage is improved, but the ability to collect sound from specific directions deteriorates

Engineering Contradiction:
Improvesound collection coverageVSAvoiddirectional sound collection capability
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The microphone system is divided into multiple independent microphone arrays, each capable of being controlled separately. This segmentation allows the system to switch between different sound collection patterns (omnidirectional vs. directional) by activating specific arrays, thereby resolving the contradiction between comprehensive coverage and directional precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sound collection directivity is made dynamic and adjustable rather than fixed. The system can change its sound collection pattern in real-time based on the operational mode, transitioning from collecting sound from all directions to collecting sound from specific directions as needed.

Inventive Principle:
Principle #15Dynamics

2Productivity

If microphones are positioned to collect sound from all directions, then overall sound collection is improved, but audio feedback and echo increase due to speaker sound being collected

Engineering Contradiction:
Improvesound collection efficiencyVSAvoidaudio feedback and echo
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

Different microphone arrays are assigned different functional roles based on their spatial positions. Some arrays are designated for general sound collection while others are specifically positioned to avoid capturing speaker output. This local differentiation allows the system to maintain high sound collection efficiency while minimizing feedback and echo from the speaker.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system converts the potentially harmful effect of speaker sound being collected into a beneficial spatial arrangement. By strategically positioning certain microphone arrays, the speaker's sound emission pattern is exploited to naturally exclude feedback paths, turning the speaker-microphone spatial relationship into an advantage for reducing audio feedback.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If fixed microphone positions are used, then device structure is simplified, but flexibility in adjusting sound collection range deteriorates

Engineering Contradiction:
Improvemicrophone array configurationVSAvoidsound collection range adjustment
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The microphone array configuration is made dynamically adjustable through rotational mechanisms. The arrays can be rotated to different angular positions, allowing the system to adapt its sound collection range and direction according to different usage scenarios while maintaining a relatively simple base structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The same microphone array structure serves multiple functions by being rotatable. A single array configuration can be positioned to achieve different sound collection patterns (omnidirectional, directional, focused on specific angles), eliminating the need for multiple fixed arrays and reducing overall device complexity while maintaining versatility.

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

Data Source

PatentEP2262278B1Speech processing device
Publication Date: 2013.07.10 YAMAHA CORP
  • EP2262278B1 patent drawingFigure 1
  • EP2262278B1 patent drawingFigure 2
  • EP2262278B1 patent drawingFigure 3

AI summary

There is provided a sound processing apparatus capable of changing the sound collection range according to a use case of a user. A sound emission and collection device 1 is mechanically configured by a main housing 10 with a triangular shape and two sub-housings 11 and 12 with approximately rectangular parallelepiped shapes. In the main housing 10, speakers SP are provided approximately in the vicinity of the center, and a microphone array 1150 which has a region from a front direction side wall to the outside as a sound collection region is provided. Microphone arrays 1151 and 1152 are provided in the sub-housings 11 and 12 respectively in a state that the microphone arrays 1151 and 1152 are in contact with different side walls of the main housing 10. Sound collection directions of the microphone arrays 1151 and 1152 are outer directions which are opposite a side of the main housing 10. In addition, the sub-housings 11 and 12 are rotatably connected to the main housing 10. The sound emission and collection device 1 generates a plurality of collected sound beam signals MB10 to MB12 based on a collected sound of each of the microphone arrays 1150 to 1152 according to the rotation amounts of the sub-housings 11 and 12 with respect to the main housing 10 and performs phase control and addition processing.