Earpiece Ambient Sound Control via Dynamic Filter Sequences
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Solution Overview
Problem
Existing headphones lack effective control over ambient sound volume, often resulting in unnatural sound perception when attempting to hear the environment, with current solutions either canceling noise entirely or providing artificial sound experiences.
Innovation Solution
An earpiece design incorporating a feed-forward microphone, feedback microphone, speaker, digital signal processor, and a memory storing an ordered sequence of filters that allow for controlled ambient sound pass-through or cancellation, enabling users to adjust the volume of ambient sound while preserving its naturalness, using a sequence of filters that provide varying frequency-dependent sound manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If active noise cancellation is used to block ambient noise, then noise reduction is improved, but the ability to hear the natural environment deteriorates
Solution Approach 1:
The patent implements dynamic switching between different filter sets based on user needs. The system transitions from static noise cancellation to dynamic adaptability by allowing users to select from multiple filter configurations (first, second, third filter sets) that provide different levels of ambient sound pass-through, thus resolving the contradiction between noise reduction and natural sound perception.
Solution Approach 2:
The patent changes the acoustic parameters by providing multiple filter sets with different frequency response characteristics. Each filter set (first, second, third) has distinct parameters for ambient sound transmission, allowing the system to adjust the degree of noise cancellation and ambient sound pass-through to balance noise reduction with natural sound perception.
2Ease of operation
If ambient sound pass-through is increased to hear the environment, then natural sound perception is improved, but noise reduction deteriorates
Solution Approach 1:
The system dynamically adjusts the balance between ambient sound pass-through and noise reduction by switching between different filter sets. Users can transition from the first filter set (more noise reduction) to the second or third filter sets (more ambient sound pass-through) depending on their current environmental needs, resolving the contradiction dynamically rather than statically.
Solution Approach 2:
Different filter sets are designed with specific parameter configurations for different listening scenarios. The first filter set optimizes for noise reduction, while the second and third filter sets optimize for ambient sound perception, allowing parameter changes to resolve the contradiction between these two opposing requirements.
3Adaptability or versatility
If discrete filter sets are used for ambient sound control, then adaptability is improved, but sound smoothness between filters deteriorates
Solution Approach 1:
The patent implements dynamic transitions between discrete filter sets to create a smooth auditory experience. While the filter sets themselves are discrete (first, second, third), the system uses crossfading or gradual parameter transitions during switching to maintain sound level continuity, thus resolving the contradiction between adaptability and smoothness.
4Ease of operation
If frequency-dependent filtering is applied to ambient sound, then sound quality is improved, but device complexity increases
Solution Approach 1:
The patent segments the frequency spectrum into different bands and applies specific filtering characteristics to each band within each filter set. This segmentation allows for improved sound quality through frequency-dependent processing while managing complexity by using pre-computed filter sets rather than real-time complex processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables users to adjust ambient sound volume seamlessly from minimal to natural levels, maintaining spectral balance and natural sound quality, effectively providing a volume control over the external environment without distorting sound properties.
Implementation Method 1
a feed-forward microphone coupled to the environment outside the headphones, a feedback microphone coupled to an ear canal of a user when the earpiece is in use
Implementation Method 2
a digital signal processor implementing feed-forward and feedback noise compensation filters between the respective microphones and the speaker
Data Source
AI summary
An earpiece includes a feed-forward microphone coupled to the environment outside the headphones, a feedback microphone coupled to an ear canal of a user when the earpiece is in use, a speaker coupled to the ear canal of the user when the earpiece is in use, a digital signal processor implementing feed-forward and feedback noise compensation filters between the respective microphones and the speaker, and a memory storing an ordered sequence of sets of filters for use by the digital signal processor. Each of the sets of filters includes a feed-forward filter that provides a different frequency-dependent amount of sound pass-through or cancellation, which in combination with residual ambient sound reaching the ear results in a total insertion gain at the ear of a user.