Hybrid Hearing Aid Combining CIC Pinna Cues with BTE Beamforming
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Solution Overview
Problem
Current hearing devices, such as IIC and CIC styles, face challenges in performing traditional beamforming due to the lack of multiple microphones, leading to issues like latency and loss of cues. Additionally, BTE/RITE style devices provide more amplification but with limitations in pinna models, which only offer 2D horizontal plane information, lacking the accuracy of 3D pinna location and high-frequency cues necessary for accurate sound localization.
Innovation Solution
The proposed solution combines the strengths of CIC and BTE/miniRITE hearing devices by utilizing the Pinna cues from the CIC device and integrating them with the beamforming and higher amplification levels of BTE/miniRITE devices. This is achieved by decomposing sound into an envelope and fine structure, using the envelope from the CIC microphone and combining it with the fine structure from the BTE/RITE device, either mathematically or after beamforming using a post-filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a CIC/IIC hearing device with a single microphone in the ear canal is used, then the device is compact and fits well in the ear canal, but traditional beamforming cannot be performed leading to latency and loss of cues
Solution Approach 1:
The patent combines a CIC-style hearing device (with ear canal microphone for pinna cues) and a BTE-style hearing device (with external microphones for beamforming) into a single hybrid device. The CIC part provides compact form factor and pinna cues, while the BTE part provides beamforming capability and amplification, resolving the contradiction between device compactness and beamforming reliability.
2Power
If a BTE/RITE hearing device is used to provide higher amplification, then sufficient amplification for wide range of people with hearing loss is achieved, but pinna models only provide 2D horizontal plane information lacking 3D location accuracy
Solution Approach 1:
The patent merges the amplification capability of BTE devices with the 3D pinna cues from CIC devices. The CIC microphone captures authentic pinna reflections that provide vertical and horizontal localization information, while the BTE amplification system provides sufficient gain for hearing loss compensation, achieving both high amplification and accurate 3D sound localization.
Solution Approach 2:
The patent uses an intermediary signal processing approach where the CIC microphone signal (containing pinna cues) is processed separately and combined with the BTE microphone signals. The pinna cues from the CIC device serve as an intermediary that enriches the spatial information of the amplified sound, enabling accurate 3D localization while maintaining high amplification levels.
3Measurement precision
If pinna cues are extracted and applied to the first electric input signal, then sound localization is improved, but feedback risk increases
Solution Approach 1:
The patent segments the hearing device into distinct CIC and BTE parts with separate signal processing paths. The CIC part processes pinna cues independently, while the BTE part handles amplification and feedback control. This segmentation allows pinna cue extraction without directly amplifying the CIC signal, reducing feedback risk while maintaining localization accuracy.
Data Source
AI summary
A hearing aid includes a forward path for processing sound from the user's environment. The forward path includes a) a first microphone providing a first electric input signal representing sound as received at the first microphone, the first microphone being located away from an ear canal of the user, b) an audio signal processor for processing the first electric input signal, or a signal or signals originating therefrom, and for providing a processed signal, c) an output transducer for providing stimuli perceivable as sound to the user in dependence of the processed signal, and d) a second microphone configured to provide a second electric input signal representing sound received at the second microphone, the second microphone being located at or in the user's ear canal, and e) a feature extractor for extracting acoustic characteristics of the user's ear from the second electric input signal, or a signal originating therefrom.