Headphone Equalization via Impedance Sensing and Model Detection

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Solution Overview

Problem

Existing audio signal processing technologies fail to consistently improve audio quality across a wide variety of sound transducers, such as headphones, due to limitations in identifying and adapting to specific headphone models, leading to suboptimal frequency responses and user dissatisfaction.

Innovation Solution

An apparatus and method that utilize image recognition, impedance measurement, and spread spectrum identification to automatically determine equalization parameters for sound transducers, allowing for user-friendly adjustment and improved audio quality without requiring manual selection from a long list of options.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a standardized interface is used to allow any headphone to be attached to any device, then compatibility is improved, but audio quality deteriorates due to poor matching between device and headphones

Engineering Contradiction:
ImprovecompatibilityVSAvoidaudio quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system measures the impedance of the connected headphones and uses this feedback to automatically identify the headphone model and select appropriate equalization parameters, resolving the mismatch between standardized interfaces and customized audio quality requirements

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the equalization parameters based on the identified headphone model, adjusting the audio signal processing to match the specific frequency response characteristics of each headphone type

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If manual selection of headphone model is required to select appropriate equalization parameters, then audio quality is improved, but ease of operation deteriorates due to the need to manually select from a long list

Engineering Contradiction:
Improveaudio qualityVSAvoidease of operation
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The system performs automatic headphone identification and equalization parameter selection without requiring user intervention, using impedance measurement to self-determine the appropriate settings

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system replaces the manual mechanical selection process with an automated electronic identification system that uses impedance measurement and database matching to automatically select equalization parameters

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If a large database of equalization parameters for many headphone models is stored locally, then adaptability is improved, but device complexity and storage requirements increase

Engineering Contradiction:
Improvenumber of supported modelsVSAvoiddatabase storage requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system extracts only the essential impedance characteristics from the headphone measurement and uses these extracted features to query a database, rather than storing and comparing complete equalization curves for every possible headphone model

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes the representation of headphone characteristics from complete frequency response curves to simplified impedance parameters, reducing the data dimensionality and storage requirements while maintaining identification accuracy

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3606093B1Apparatus for providing an audio signal for reproduction by a sound transducer, system, method and computer program
Publication Date: 2021.09.08 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3606093B1 patent drawingFigure 1
  • EP3606093B1 patent drawingFigure 2
  • EP3606093B1 patent drawingFigure 3

AI summary

An apparatus (100) for processing an input audio signal (122) for reproduction by a sound transducer (130) comprises an equalization parameter determinator (110) for determining a set of equalization parameters (112) and an equalizer (120) configured to equalize the input audio signal (122), to obtain an equalized audio signal (124). Different concepts for the determination of the set of equalization parameters (112) comprise an image recognition, an evaluation of an identification signal which is provided by the sound transducer via an audio connection, and a measurement of the impedance of the sound transducer over frequency. Also, an upload functionality and a download functionality are provided.