Signal Processing Apparatus for Ear-Canal Noise Cancellation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional noise canceling technologies face challenges in achieving optimal noise reduction at the eardrum position due to difficulties in arranging microphones at this location, resulting in suboptimal usability.

Innovation Solution

A signal processing apparatus that acquires acoustic characteristics in a user's ear, generates sound data with a phase opposite to ambient noise, corrects this data using a correction filter, and determines the filter coefficient based on the acquired acoustic characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a microphone is arranged at the eardrum position to maximize noise canceling effect, then the noise reduction performance is improved, but the device complexity and manufacturing difficulty increase due to product specifications constraints

Engineering Contradiction:

Improvenoise canceling effectVSAvoidmicrophone arrangement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses acoustic simulation to create a virtual copy of the eardrum position acoustic characteristics. Instead of placing a microphone physically at the eardrum, the system measures acoustic data from multiple positions and uses simulation to replicate what the eardrum would experience, thereby achieving the desired measurement without the physical constraint

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent introduces an acoustic simulation model as an intermediary between the microphone and the eardrum position. This model translates acoustic measurements from accessible locations into equivalent eardrum-position data, serving as a mediator that bridges the gap between measurement capability and the desired measurement location

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If standard microphone positions are used due to product specifications, then the ease of manufacture is improved, but the noise canceling performance at the eardrum position deteriorates

Engineering Contradiction:

Improvemicrophone placement simplicityVSAvoidnoise reduction at eardrum

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the mechanical approach of physically placing a microphone at the eardrum with a computational/acoustic simulation approach. Instead of using a physical microphone at the target position, the system uses acoustic field simulation to mathematically determine the acoustic characteristics at the eardrum position based on measurements from standard microphone locations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the measurement parameters by changing from direct physical measurement at the eardrum to indirect measurement at standard positions combined with simulation. The system measures acoustic parameters at accessible locations and then transforms these parameters through simulation to obtain the equivalent eardrum-position parameters

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If acoustic characteristics are measured at standard positions, then the ease of operation is improved, but the measurement precision for eardrum position acoustic characteristics deteriorates

Engineering Contradiction:

Improvemeasurement procedure simplicityVSAvoidacoustic characteristic accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent employs feedback through acoustic simulation to verify and adjust the measured characteristics. The system measures acoustic data, inputs it into the simulation model, and uses the simulated results to refine the understanding of eardrum-position characteristics, creating a feedback loop that enhances measurement accuracy

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent performs preliminary acoustic measurements at standard microphone positions before conducting the actual eardrum-position characterization. These preliminary measurements serve as input data for the simulation, allowing the system to prepare and process acoustic information in advance to achieve precise eardrum-position characterization

Inventive Principle:

Principle #10Preliminary action

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 approach enables personalized noise optimization, improving the noise canceling effect by adapting to individual ear characteristics and wearing conditions, thus enhancing usability.

Implementation Method 1

an NC filter unit that generates sound data having a phase opposite to an ambient sound leaking into the user's ear

Methodology Applied

Scientific EffectPhase inversion:

Implementation Method 2

a correction unit that corrects the sound data by using a correction filter

Methodology Applied

Scientific EffectFiltering: Filter (electronic)

Data Source

PatentUS12300210B2Signal processing apparatus, signal processing method, signal processing model production method, and sound output device

Publication Date: 2025.05.13 SONY GROUP CORP

AI summary

Provided is a signal processing apparatus including an acquisition unit that acquires an acoustic characteristic in a user's ear, isolated from the outside world and an NC filter unit that generates sound data having a phase opposite to an ambient sound leaking into the user's ear. The signal processing apparatus further includes a correction unit that corrects the sound data by using a correction filter and a determination unit that determines a filter coefficient of the correction filter based on the acoustic characteristic.