ANC Earphone Self-Calibration Case for Consistent Noise Cancellation

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Solution Overview

Problem

Audio listening devices, such as headphones and earphones, experience degradation over time due to wear and tear, leading to shifts in performance parameters like frequency response and noise cancellation, which are not adequately addressed by one-time calibration during manufacturing.

Innovation Solution

A self-calibration system using a housing with a calibration circuit, microphone, and speaker to recreate an acoustic environment for recalibrating earphones, allowing users to maintain optimal audio quality and noise cancellation through repeated calibration processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If one-time calibration is performed during manufacturing, then initial audio quality meets design specifications, but audio performance degrades over time due to wear and tear

Engineering Contradiction:
Improveaudio quality consistencyVSAvoiddevice lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system enables self-calibration by incorporating a calibration speaker and calibration microphone within the housing that work automatically when the earphone is placed in the housing. The calibration speaker emits test tones and the calibration microphone captures the output, allowing the system to automatically adjust and recalibrate the earphone's audio parameters without external intervention, thus maintaining audio quality throughout the device lifespan

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The calibration process is designed to be performed periodically whenever the earphone is placed in the housing (such as during charging), rather than only once during manufacturing. This periodic recalibration compensates for degradation accumulated over time, maintaining consistent audio performance throughout the device's operational life

Inventive Principle:
Principle #19Periodic action

2Reliability

If professional recalibration is required to maintain audio quality, then audio performance can be maintained, but user convenience is reduced and accessibility is limited

Engineering Contradiction:
Improveaudio quality consistencyVSAvoidcalibration accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-calibration automatically when the earphone is placed in the housing, eliminating the need for users to seek professional calibration services. The integrated calibration speaker and microphone work autonomously to adjust audio parameters, making the process as convenient as placing the earphone in its case

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The housing acts as an intermediary calibration station that provides the controlled acoustic environment and calibration equipment normally available only in professional settings. By embedding the calibration speaker and microphone in the housing, the system brings professional calibration capabilities to the consumer level

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables consumers to recalibrate their earphones regularly, ensuring consistent audio performance and noise cancellation without the need for professional recalibration, extending the device's lifespan.

Implementation Method 1

a calibration speaker configured to emit calibration sound waves to the ANC earphone

Methodology Applied
Scientific EffectElectroacoustic transduction:

Implementation Method 2

a calibration microphone coupled with the first calibration circuit and configured to capture calibration sound waves from the ANC earphone

Methodology Applied
Scientific EffectAcoustoelectric transduction:

Data Source

PatentEP4049465B1System and method for self-calibrating audio listening devices
Publication Date: 2026.04.22 GOOGLE LLC
  • EP4049465B1 patent drawingFigure 1~2
  • EP4049465B1 patent drawingFigure 3
  • EP4049465B1 patent drawingFigure 4

AI summary

A self-calibration system may include a housing including a first calibration circuit configured to coordinate with a second calibration circuit to execute a calibration sequence for an active noise cancelling (ANC) earphone. The housing further includes a cavity configured to accommodate the ANC earphone, wherein the cavity is contoured to simulate the ANC earphone in a user's ear. The housing further includes a calibration microphone coupled with the first calibration circuit and configured to measure calibration sound waves from the ANC earphone, and a calibration speaker configured to emit calibration sound waves to the ANC earphone.