Hearing Aid Speech Gain Balancing to Mitigate the Lombard Effect

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Solution Overview

Problem

Hearing aid users often experience difficulty understanding their conversation partners due to background noise, leading to the Lombard effect where they unconsciously speak louder, causing discomfort for both parties.

Innovation Solution

A hearing aid system that separates user's speech and conversation partner's speech using spatial analysis or frequency methods, applies different gain factors to each signal component, and adjusts the second gain factor to equalize the levels of the processed signals, preventing excessive shifts and improving intelligibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If automatic amplification is active to ensure sounds are audible, then user comfort is improved, but the user speaks louder due to the Lombard effect causing loss of comfort for the conversation partner

Engineering Contradiction:
Improveuser comfortVSAvoidLombard effect
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent segments the audio signal into two distinct components: the user's speech and the conversation partner's speech. By separating these signals, the system can apply different processing and gain control to each, allowing the user's speech to be amplified for their own benefit while the conversation partner's speech is handled differently to prevent the Lombard effect from escalating

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different gain factors to different signal components based on their local characteristics. Specifically, the first gain factor is applied to the user's speech component while the second gain factor is applied to the conversation partner's speech component. This localized processing allows optimal amplification for each speaker's needs without causing the harmful feedback loop of the Lombard effect

Inventive Principle:
Principle #3Local quality

2Measurement precision

If the user speaks louder to overcome background noise, then understanding of the conversation partner improves, but comfort for the conversation partner deteriorates

Engineering Contradiction:
Improvespeech intelligibilityVSAvoidconversation partner comfort
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent implements a feedback mechanism where the system continuously monitors the audio signal, identifies the conversation partner's speech component, and adjusts the second gain factor in response to the detected speech levels. This feedback loop prevents the conversation partner from needing to speak louder by ensuring their speech is clearly transmitted to the user, thereby breaking the Lombard effect cycle while maintaining speech intelligibility

Inventive Principle:
Principle #23Feedback

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

Enhances user comfort and improves conversation clarity by ensuring the user can understand their conversation partner without needing to speak louder, mitigating the Lombard effect.

Implementation Method 1

The hearing aid comprises a microphone for detecting ambient sound... The microphone is suitably an electromechanical transducer... Each of the microphone units advantageously has a diaphragm that is set into vibration by sound waves, and the vibrations are converted into an electrical signal by means of a suitable recording device, such as a magnet moved within a coil.

Methodology Applied
Scientific EffectElectromechanical transduction:

Data Source

PatentEP4661433A1Method for operating a hearing aid
Publication Date: 2025.12.10 SIVANTOS PTE LTD
  • EP4661433A1 patent drawingFigure 1
  • EP4661433A1 patent drawingFigure 2~3
  • EP4661433A1 patent drawingFigure 4~5

AI summary

The invention relates to a method (14) for operating a hearing aid (2) in which an input signal (20) is generated from ambient sound (18). A first signal component (32) and a second signal component (43) are extracted from the input signal (20), wherein the first signal component (32) corresponds to speech (22) of a user and the second signal component (34) corresponds to speech (24) of another person. A first processed signal (42) is generated from the first signal component (32) and a first gain factor (40), and a second processed signal (54) is generated from the second signal component (34) and a second gain factor (52). The two processed signals (42, 54) are combined to form an output signal (80). The second gain factor (52) is selected depending on a difference (48) between the level of the first processed signal (42) and the level of the second processed signal (54).Furthermore, the invention relates to a hearing aid (2).