Hearing Device Directional System Phase Distortion Reduction
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Solution Overview
Problem
Existing hearing devices face challenges in minimizing phase distortion in directional signals, which affects the separation of target and noise signals in audio applications like hearing aids and communication devices.
Innovation Solution
A hearing device with a beamformer output unit that includes an adaptive algorithm and filter to equalize beamformed signals for phase and amplitude differences, optimizing the beamformed output signal by minimizing energy or amplitude fluctuations, and using a directional microphone system to enhance target signal detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If beamforming is applied to enhance target signal over noise, then noise suppression is improved, but phase distortion is introduced in the directional signal
Solution Approach 1:
The patent segments the beamforming process into multiple independent stages: directional signal creation, phase distortion measurement, and separate compensation. By dividing the processing into frequency-dependent stages and using multiple microphones with independent processing paths, the system can suppress noise while preserving phase information through targeted compensation in each segment.
Solution Approach 2:
The patent changes parameters dynamically by measuring phase distortion characteristics across different frequencies and adapting compensation filters accordingly. The system adjusts filter coefficients based on measured phase differences between microphones, transforming the fixed beamforming approach into an adaptive parameter-based solution that maintains signal integrity.
2Measurement precision
If directional processing is applied to separate target and noise signals, then target signal detection is enhanced, but signal separation precision deteriorates due to phase distortion
Solution Approach 1:
The patent implements feedback by measuring the actual phase distortion introduced by the directional processing and using this measurement to generate compensating filters. The system continuously monitors phase differences between microphone signals and adjusts compensation parameters accordingly, creating a closed-loop system that maintains separation precision despite directional processing.
Solution Approach 2:
The patent combines multiple processing components into a composite system: directional beamforming filters for noise suppression, phase measurement mechanisms for characterization, and compensation filters for correction. This composite approach integrates multiple functions that work together to achieve both enhanced detection and maintained separation precision.
Data Source
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AI summary
The application relates to a hearing device comprising an input unit for providing first and second electric input signals (I1, I2) representing sound signals, a beamformer filter (BF) for making frequency-dependent directional filtering of the electric input signals (I1, I2), the output of said beamformer filter (BF) providing a resulting beamformed output signal (RBFS). The application further relates to a method of providing a directional signal. The object of the present application is to create a directional signal. The problem is solved in that the beamformer filter (BF) comprises a directional unit (DIR) for providing respective first and second beamformed signals (ID1, ID2) from weighted combinations of the electric input signals (I1, I2), an equalization unit for equalizing a phase (and possibly an amplitude) of the beamformed signals (ID1, ID2) and providing first and second equalized beamformed signals (IDE1, IDE2), and a beamformer output unit (BOU) for providing the resulting beamformed output signal (RBFS) from the first and second equalized beamformed signals (IDE1, IDE2). This has the advantage to create a directional signal where the phase of the individual components is preserved, and therefore introducing no phase distortions. The invention may e.g. be used in hearing aids, headsets, ear phones, active ear protection systems, and combinations thereof.