ANR Earphone Howling Suppression via Microphone Signal Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Active Noise Reduction (ANR) earphones often produce howling due to positive feedback, which can damage components and cause user discomfort, and current methods can only detect howling after it has started, allowing for a short period of transitory howling before intervention.
Innovation Solution
A howling suppression method that uses the relationship between signals from a reference microphone outside the auditory meatus and an error microphone inside to determine if an ANR earphone is in a state capable of producing howling, allowing for immediate processing to prevent howling production, thereby avoiding damage and discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current howling detection methods are used, then howling can be detected after it has started, but a short period of transitory howling occurs before intervention, causing component damage and user discomfort
Solution Approach 1:
The patent calculates the transfer function from the reference microphone to the error microphone in advance and determines whether the system is in a howling-prone state before actual howling occurs. This preliminary assessment allows the system to take preventive measures ahead of time, eliminating the detection delay and preventing component damage and user discomfort.
2Reliability
If the relationship between reference microphone and error microphone signals is analyzed, then the state capable of producing howling can be determined in advance, but the system complexity increases
Solution Approach 1:
The patent establishes a feedback mechanism where the error microphone signal is continuously compared with the reference microphone signal to calculate the transfer function. This feedback loop enables real-time monitoring of the system state and automatic detection of howling-prone conditions, improving reliability while maintaining manageable complexity through standardized processing algorithms.
Data Source
Figure 1~2B
Figure 2C~4
Figure 5~6
AI summary
The present invention discloses a howling suppression method and device applied to an ANR earphone. The method comprises: collecting signals by using a first microphone and a second microphone; wherein the first microphone is arranged in a position outside an auditory meatus when said ANR earphone is worn, and the second microphone is arranged in a position inside the auditory meatus when the ANR earphone is worn; according to a relation between signals collected by the first microphone and the second microphone, judging whether the current state of said ANR earphone is a state unable to produce a howling or a state able to produce a howling; and when the current state of said ANR earphone is a state able to produce a howling, starting processing for preventing howling production. The technical scheme can achieve that the ANR earphone does not produce a howling all the time.