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US 11,889,257 B2Granted
Wearable audio device zero-crossing based parasitic oscillation detection
AssigneeBose Corporation
InventorEmery M. Ku
Life of this patent
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Abstract
A method for detecting and mitigating parasitic oscillation in a headphone equipped with an active noise reduction (ANR) system. A fundamental frequency of a microphone signal is determined from a microphone of the ANR system and an amplitude of the determined fundamental frequency is compared to a threshold level to determine parasitic oscillation. If parasitic oscillation is determined, then the microphone signal is altered to mitigate the parasitic oscillation.
Claims25
A method for detecting and mitigating parasitic oscillation in a headphone equipped with an active noise reduction (ANR) system, the method comprising:
- determining a fundamental frequency of a microphone signal from a microphone of the ANR system;
- and
- comparing an amplitude of the determined fundamental frequency to a threshold level to determine parasitic oscillation;
- and
- if parasitic oscillation is determined, then altering the microphone signal to mitigate the parasitic oscillation.
2 more elements
A method comprising:
- mapping a distance between zero crossings of a microphone signal at a processor sampling speed to detect a fundamental frequency of the microphone signal;
- comparing the detected fundamental frequency to a predetermined frequency range;
- if the fundamental frequency is within the predetermined frequency range, then comparing a magnitude of the microphone signal to a predetermined threshold;
- if the magnitude of the microphone signal is above the predetermined threshold, then determining if the magnitude of the microphone signal remains above the predetermined threshold for a predetermined time duration to determine parasitic oscillation;
- and
- if the magnitude of the microphone signal remains above the predetermined threshold for the predetermined time duration, then mitigating the parasitic oscillation.
3 more elements
Dependencies are inferred from the claim text.