Directionality Testing Apparatus for Hearing Instruments
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Solution Overview
Problem
Advanced hearing instruments with adaptive signal processing algorithms often suppress pure tone test signals, leading to inaccurate directionality measurements, and existing methods using broad spectrum signals or noise-based tests are not effective in simulating real-life scenarios.
Innovation Solution
An apparatus and method for testing directional hearing instruments using natural signals like speech or traffic noise from multiple directions, allowing for cross spectrum analysis to determine hearing instrument parameters and simulate real-life situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pure tone test signals are used to test directionality, then the test is simple and straightforward, but the signals are suppressed by adaptive algorithms leading to inaccurate measurements
Solution Approach 1:
The patent changes the fundamental parameter of the test signal from pure tones to broadband noise signals. This parameter change allows the signal to be recognized as non-speech by adaptive algorithms, preventing suppression while still enabling directionality measurement through cross-correlation analysis of the noise signal and hearing instrument output.
Solution Approach 2:
The patent introduces an intermediary processing step using cross-correlation analysis. Instead of directly measuring the suppressed pure tone response, the system uses cross-correlation between the broadband noise signal and the hearing instrument output as an intermediary method to extract directionality information without being affected by algorithmic suppression.
2Measurement precision
If broadband excitation signals are used to avoid suppression, then measurement accuracy improves, but the complexity of the testing apparatus increases
Solution Approach 1:
The patent makes the hearing instrument itself serve multiple functions: it acts as both the device being tested and as part of the measurement system. The hearing instrument's own microphone and processor are used to capture and analyze the broadband noise signal, eliminating the need for separate external measurement devices and reducing overall system complexity.
Solution Approach 2:
The hearing instrument performs self-measurement of its directionality characteristics using its own internal components. The device processes the broadband noise signal through its own algorithm and uses its own microphone to capture the output, allowing it to self-evaluate its directional performance without requiring external test equipment.
3Adaptability or versatility
If natural signals like speech are used to simulate real-life situations, then the test becomes more realistic, but the signal processing algorithms may still suppress the test signal
Solution Approach 1:
The patent changes the signal type parameter from structured speech signals to broadband noise signals. This parameter change ensures the signal is classified as non-speech by adaptive algorithms, preventing suppression while maintaining the ability to simulate real-life directional listening scenarios through the use of natural broadband noise environments.
Data Source
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AI summary
Disclosed are an apparatus and a method for testing a directional hearing instrument. The apparatus comprising: a first microphone for coupling with an output of the hearing instrument; a first speaker for transmission of a first signal; a second speaker for transmission of a second signal. The apparatus is configured to: transmit the first signal, the first signal having a first frequency component at a first frequency; transmit the second signal, the second signal having a second frequency component at a second frequency; receive an audio output signal from the hearing instrument, and determine one or more hearing instrument parameters based on cross spectrum analysis of the first signal and the audio output signal.