Headphone Signal Processing for Individual Ear Seal Compensation
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Solution Overview
Problem
Existing noise reduction systems for headphones fail to account for individual differences in head shape, ear size, and wearing styles, leading to varying audio signal characteristics and reduced noise reduction effectiveness.
Innovation Solution
A signal processing apparatus that collects sound from the headphone driver, compares its characteristics with intended audio signal characteristics, and adjusts the sound quality using personalized filters to ensure the desired sound quality is maintained regardless of individual differences in head shape and wearing style.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If noise reduction processing is applied using a fixed audio signal characteristic, then the noise reduction effect can be provided, but the sound quality varies among different listeners due to individual differences in head shape, ear size, and wearing style
Solution Approach 1:
The patent applies dynamics by making the audio signal characteristic adjustable based on listener feedback. The system dynamically changes the audio signal characteristic according to the difference between expected sound pressure level and actual sound pressure level measured by the microphone, thereby adapting to individual differences in head shape, ear size, and wearing style while maintaining consistent sound quality across different listeners
Solution Approach 2:
The patent implements feedback by using a microphone to measure the actual sound pressure level inside the ear canal and comparing it with the expected sound pressure level. The system then adjusts the audio signal characteristic based on this feedback to compensate for individual differences, ensuring that each listener receives the intended sound quality while maintaining the noise reduction effect
2Adaptability or versatility
If the audio signal characteristic is adjusted for each listener, then sound quality consistency can be achieved, but the system complexity increases
Solution Approach 1:
The patent applies universality by using a single adjustable audio signal characteristic parameter that serves multiple functions. This parameter controls both the noise reduction effect and the sound quality adaptation to individual differences. By making this one parameter adjustable, the system achieves personalized sound quality for different listeners without requiring completely separate processing paths, thereby limiting the increase in system complexity
Data Source
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AI summary
[Object] To provide a signal processing apparatus which can allow a user to listen to sound assumed by a designer while a difference among individuals is taken into account. [Solution] Provided is a signal processing apparatus including: a characteristics difference calculating unit configured to calculate a difference between reproduction target characteristics of a first sound signal and characteristics of a second sound signal obtained by collecting, at a microphone provided inside a headphone, sound output from a driver which outputs the sound based on a third sound signal obtained by performing signal processing on the first sound signal; and a sound signal processing unit configured to select a parameter to be used at the signal processing based on the difference calculated by the characteristics difference calculating unit, and perform signal processing on the first sound signal.