Ear Canal Voice Spectral Correction for Loose-Fit Earbuds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio signal processing systems in wearable devices like earbuds or earphones face issues with inconsistent voice capture due to loose fitting of earbuds and the use of active ANC units, leading to reduced low-frequency components and boosted mid-frequency components, affecting voice quality and applications such as voice activity detection and speech recognition.
Innovation Solution
A method and system that involves determining the spectral center of the internal audio signal, applying a spectrum shape correction filter to mitigate the effects of loose fitting and active ANC units by boosting low-frequency components and reducing mid/high-frequency components, using filters like low-shelf and high-shelf bi-quad filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor is disposed inside an ear canal to measure acoustic characteristics, then measurement precision is improved, but device complexity and user comfort worsen due to intrusion into the ear canal
Solution Approach 1:
A probe is introduced as an intermediary component that transmits acoustic signals from the ear canal environment to the sensor. The probe acts as a mediator between the measurement environment (ear canal) and the sensing element, allowing accurate measurement without requiring the sensor to be directly inserted into the ear canal, thus reducing device complexity and improving user comfort.
2Measurement precision
If a sensor is disposed inside an ear canal to measure acoustic characteristics, then measurement precision is improved, but ease of operation worsens due to insertion and removal procedures
Solution Approach 1:
The probe serves as a removable intermediary that can be easily inserted and removed from the ear canal, while the main sensor unit remains external. This separation allows the probe to be quickly exchanged for measurements without requiring complex insertion procedures for the entire sensor system, significantly improving ease of operation.
3Adaptability or versatility
If ear canal acoustic characteristics are used for audio signal processing, then adaptability is improved for personalized audio, but measurement reliability worsens due to variations in ear canal conditions
Solution Approach 1:
The system performs preliminary measurements of the ear canal acoustic characteristics before actual audio playback. By capturing the transfer function in advance and storing it for later use, the system ensures consistent reference data is available for audio signal processing, reducing variability caused by real-time ear canal condition changes and improving measurement reliability.
Solution Approach 2:
The system uses feedback from the measured ear canal acoustic characteristics to adjust and optimize audio signal processing parameters. The measured transfer function is used to compensate for individual ear canal variations, creating personalized audio output that adapts to each user's unique acoustic environment, thereby improving adaptability while maintaining reliability through continuous optimization.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present disclosure relates to an audio signal processing method implemented by an audio system which includes at least an internal sensor, wherein the internal sensor is located in an ear canal of a user of the audio system and arranged to measure acoustic signals which propagate internally to a head of the user. The audio signal processing method includes: producing an internal audio signal by the internal sensor; determining an audio spectrum of the internal audio signal; determining a spectral center of the audio spectrum; determining a spectrum shape correction filter based on the spectral center; and filtering the internal audio signal by using the spectrum shape correction filter, thereby producing a filtered internal audio signal.