How Rehear Audiology is Redefining Hearing Solutions with Advanced Noise Cancellation and AI

2024/12/27

How Rehear Audiology is Redefining Hearing Solutions with Advanced Noise Cancellation and AI

Thank you very much to Business Weekly for the interview, giving us the opportunity to share how Rehear Audiology leverages advanced active noise cancellation and AI technologies to pioneer a new era of integrated hearing solutions.

How Rehear Audiology is Redefining Hearing Solutions with Advanced Noise Cancellation and AI

Tapping into the OTC Hearing Aid Boom
By offering holistic acoustic solutions—not just ICs—Rehear Audiology (a Realtek Group subsidiary) has positioned itself as a one-stop partner for top global headphone brands.
From Chipmaker to Full-Service Provider
Beyond simply “selling chips,” Rehear has built a comprehensive ecosystem that includes AI hearing tests, in-ear measurements, hearing compensation, and active noise cancellation.
Market Education, Powered by Apple
Once Apple announced hearing assistance features for AirPods in 2024, consumer acceptance soared. Rehear seized this opportunity by demonstrating clinical-grade noise-cancellation tests in noisy environments.
Serving 80% of Users’ Needs
While battery life currently limits all-day use, Rehear’s solutions target light-to-moderate hearing-impaired users—meeting an estimated 80% of the market demand.

Key Takeaway

Rehear Audiology showcases how a strategic pivot—from core chipmaking to end-to-end acoustic solutions—can effectively tap into a rapidly expanding market. Powered by advanced noise cancellation and AI-driven features, Rehear stands ready to meet global demand for accessible and reliable OTC hearing aids.

A Study on the Benefits of Optimizing Active Noise Reduction Technology with Auditory Masking Characteristics in Hearing Test

2024/12/29

Department of Research | Rehear Audiology, Taipei, Taiwan

This paper optimizes active noise cancellation (ANC) technology based on auditory masking principles, focusing on the center frequencies of hearing assessment tones. Four scenarios were designed to assess the beneﬁts of using this technology for hearing tests in different noise environments. Experimental results, derived from objective sound measurements and subjective clinical hearing tests, show consistent outcomes across the four ANC-assisted hearing test scenarios. In high-noise environments, a higher maintained signal-to-noise ratio in the pure- tone signals corresponds to a stronger correlation between clinical hearing test thresholds and standard hearing test thresholds. The proposed optimized ANC technology outperforms both generic ANC and "ANC off" settings, regardless of whether the assessments are conducted in typical or noisy environments. Clinical experiments reveal a high degree of covariance between the measured thresholds using optimizing ANC technology and standard hearing test thresholds in everyday noise conditions.

Furthermore, the proposed method demonstrates close alignment between the average audiograms obtained from individuals with hearing impairments and the results from standard hearing tests, with differences within 10 dB at various frequencies. This indicates that the proposed method, utilizing a Hearing test APP combined with TWS earphones, is feasible for independent at-home hearing assessments, providing reliable results across diverse user proﬁles (participants ranged from 20 to 70 years old) in everyday or noisy environments. Consequently, this technology is suitable for home-based self-monitoring of hearing health.

In a high-noise environment (at 65 dB(A)), despite the challenging conditions, individuals using optimizing ANC technology demonstrated a higher number of pass results at 25 dB HL compared to those using generic ANC technology. However, there is room for improvement in achieving pass results at 500 and 1000 Hz at 25 dB HL for both ANC technologies. Future enhancements can focus on reﬁning the headphone cavity design to improve the ﬁt and alignment with the ear canal, expecting to enhance the signal-to-noise ratio at 500 and 1000 Hz and subsequently improve pass rates at 25 dB HL thresholds. In summary, optimizing ANC technology based on auditory masking principles effectively maintains a better signal-to-noise ratio in noisy environments. The proposed optimizing ANC hearing test, performed independently by participants using the provided Hearing test APP and TWS earphones, demonstrates a moderate to high correlation with standard hearing tests. This implies that the operational mode of the designed hearing assessment device can overcome user diversity and provide trustworthy results in everyday and noisy environments, serving as a tool for self-monitoring of hearing abilities.

While the optimizing ANC technology, designed based on auditory masking principles, outperforms generic ANC in noisy environments, there is still room for improvement at 500 and 1000 Hz. The development of optimizing ANC technology is time-consuming, involving manual adjustments of ANC parameters and veriﬁcation through sound measurements. Additionally, adjustments need to consider both the amplitude and phase of acoustic responses while minimizing side effects like the occlusion effect. To address these challenges, artiﬁcial intelligence and considerations of individual ear canal acoustic resonance differences can be utilized for rapid calculation of ﬁlter coeÆcients closely matching the target curve. This would enhance the ﬂexibility of ANC in adjusting its frequency range according to noise volume or speciﬁc bandwidth requirements. Referring to the design of the hearing assessment device presented in this paper, individuals can independently perform hearing tests without professional assistance, with results highly consistent with standard hearing assessments. This technology can be used as a self-ﬁtting over-the-counter hearing aid selection tool, promoting easy and accessible hearing health management. By optimizing ANC technology based on auditory masking principles, the core objective of enabling hearing tests to move beyond clinical settings can be realized.

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Over-the-counter (OTC) hearing aid regulatory verification

2024/12/29

Department of Research | Rehear Audiology, Taipei, Taiwan

In August 2022, the White House announced the OTC Hearing Aids Act in response to the growing number of people with hearing loss and the low penetration rate of hearing aids. This act offers a fresh solution for individuals with mild to moderate hearing loss, enabling easy access to hearing aids at reduced costs and improved availability. However, ensuring the safety and effectiveness of these OTC hearing aids remains the major challenge in the market.

According to the regulations established in the United States for over-the-counter hearing aids, in order to protect users' hearing, the maximum output sound pressure level for linear compensation is limited to 111 dB SPL (Sound Pressure Level in decibels). The part of the hearing aid inserted into the ear canal must be at least 10 millimeters away from the eardrum. Additionally, over-the-counter hearing aids cannot be sold to children under 18 years of age. In terms of acoustic performance, these hearing aids must comply with the ANSI S3.22 standard:

Total harmonic distortion rate is less than 5%. Internal noise is less than 32 dBA.

Signal processing delay should be less than 15 ms.

Frequency range should extend to 250 Hz or lower and 5000 Hz or higher. Frequency response curve should not exceed an average of 12 dB.

The Rehear research and development team places a strong emphasis on product safety. Throughout the product development and adjustment process, we utilize the Frye FONIX 7000 and Audioscan

veriﬁt2 for sound-electric measurements to ensure compliance with the ANSI S3.22 standards.

The measurement results of the Rehear chip are as follows:

Rehear Solution Testing Items:	Pass / Fail
Total Harmonic Distortion (THD) ratio	Pass
Equivalent Input Noise (EIN)	Pass
Signal processing delay	Pass
Frequency range	Pass

Rehear's research and development team can adjust chip parameters according to speciﬁc product requirements, enabling us to customize the chips based on particular demands. This ensures adherence to criteria such as HFA Max OSPL90, HFA full-on gain, and reference testing gains. Choosing Rehear's hearing solution grants clients access to our team's vast expertise in acoustic-electric adjustments, greatly improving the likelihood of their products meeting OTC hearing aid regulations. We are dedicated to providing personalized solutions to meet the unique needs of each client.

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Does Rehear sell chips or finished products?

2024/12/24

Rehear's primary product offerings are integrated solutions, and we do not sell finished products. Our chip solutions include exclusive algorithms, AI model access, software and hardware SOPs, and reference apps. For customers with a demand for finished products, we can recommend hardware manufacturers that we collaborate with to meet their specific needs.

How much does the chip cost?

2024/12/24

Regarding the pricing for each chip solution, please reach out to our sales channels, and we will provide you with further quotations and details.

What is hearing number? Why is it important to track hearing numbers regularly?

2024/12/24

"Hearing number measurement is an indicator that helps consumers understand their hearing status and track changes over time.
Significant shifts in hearing numbers may indicate hearing loss, prompting timely medical interventions for improvement."

Sampling Rate

2024/12/24

The sampling rate refers to the number of points used to record one second of sound fluctuations. A higher sampling rate results in more sound details, providing a more nuanced and refined audio experience. Rehear’s exclusive 625k high-quality mode enhances the audio source from Bluetooth streaming (44.1 kHz) through upsampling technology. This method uses interpolation to analyze the positions between sampling points to determine where additional points should be inserted, raising the sampling rate to 625k and enriching the sound quality.

ANC Category

2024/12/24

General active noise cancellation (ANC) typically combines feedforward and feedback microphones to reduce external noise through composite ANC. However, to fully utilize ANC algorithms, adjustments to headphone parameters are necessary. Rehear’s ANC parameter adjustment technology allows for deeper noise cancellation than original parameters.

ANC Scenarios

2024/12/24

Standard ANC parameters often fail to provide better noise cancellation depth for specific noise environments, leading to suboptimal performance when faced with different types of noise. Rehear’s ANC parameter adjustment technology allows us to optimize the ANC algorithms to achieve the best noise cancellation depth based on specified environmental noise. We have pre-selected four common noise environments for customers to choose from: commuting, aviation, coffee shop, and general noise mode. If customers have specific noise environments in mind, we can discuss those together as well.

Adjustable Channel Numbers

2024/12/24

In traditional hearing aids, a higher number of adjustable channels typically corresponds to higher-end models. The more adjustable channels available, the more points an audiologist can fine-tune the gain curve to meet the hearing needs of individuals with hearing loss. Rehear uniquely employs AI to automatically adjust 441 channels without requiring manual adjustments from audiologists.

Signal Delay

2024/12/24

The combination of system processing delays and external sounds leaking into the ear canal can create a comb-filtering effect, causing users to perceive echoes in the sound. This can ultimately make it difficult for users to adapt to the sound quality of hearing aids. Rehear, through exclusive circuit design and the assistance of AI, has reduced signal delays in Rehear mode to an industry-leading 0.2 ms. This significantly diminishes the comb-filtering effect, ensuring that the sound quality of the hearing aids remains as clear and bright as the original sound.

Power Consumption

2024/12/24

Through exclusive circuit design and AI assistance, Rehear reduces power consumption in Rehear mode by 22% compared to traditional signal processing, allowing for extremely low latency, a wide frequency response, and extended usage time.

What is the battery performance of the TWS+ and OTC chip solutions?

2024/12/24

The battery performance of TWS and OTC chip solutions is similar to mainstream Bluetooth earphones (such as Apple AirPods), providing 5-6 hours of continuous use on a single charge. Additionally, with the charging case, the total battery life can reach around 15 hours, ensuring stable performance and convenient charging for extended use.

For example, using Philips battery specifications in Rehear's TWS and OTC solutions, the battery performance is as follows:
With Bluetooth 5.3 and AAC/SBC encoding, the earphones, along with the charging case, offer a total battery life of 28 hours, suitable for daily commuting or music listening, typically requiring charging only 2-3 times per week.

Specifications:
Driver: 10mm graphene-coated dynamic driver
Frequency Range: 20 - 20,000 Hz
Dust/Water Resistance: IPX4
Bluetooth Version: 5.3
Bluetooth Codec: AAC/SBC
Maximum Range: 10 meters
Fast Charging Time: 5 minutes of charging provides 1 hour of playback
Charging Time: 2 hours
Music Playback Time: Up to 28 hours (with charging case)
Earbud Playback Time: 7 hours per charge

How does Rehear AI chip technology assist factories in automatically importing parameter settings? What benefits does it provide?

2024/12/24

Rehear’s AI chip technology incorporates AI Adapted NR for automatic calibration, replacing current manual adjustments. This reduces R&D and labor costs associated with mass production, ultimately enhancing production efficiency and ensuring quality stability.

How is AI Adapted NR applied to TWS+ and OTC HA?

2024/12/24

Active noise cancellation is one of the common features of true wireless Bluetooth headphones, allowing users to enjoy music and take calls without being disturbed by environmental noise. However, while high-end hearing aids also have the need to listen to music and take calls via Bluetooth, they cannot completely isolate external noise interference.

To address this need, Rehear utilizes AI Adapted NR technology, which allows users to select the optimal noise cancellation mode based on the environment. This helps users focus on listening to music and phone calls while also eliminating the occlusion effect during conversations when wearing the headphones.

Is AI hearing compensation accurate?

2024/12/24

Rehear’s AI hearing compensation technology has undergone rigorous electroacoustic measurement validation, ensuring precise gain compensation,
especially for individuals with mild to moderate hearing loss. Experimental results closely match normative values, confirming the accuracy of compensation effects
and ensuring the precision and stability of personalized audio hearing compensation, ultimately enhancing the auditory experience for users.

What are the differences between Rehear AI audio solutions and traditional hearing aids?

2024/12/24

Rehear’s acoustic tuning technology significantly reduces in-ear mixing, enhances speech clarity, and minimizes the impact of comb-filtering effects.
Compared to traditional hearing aids, Rehear’s ultra-low latency and high sampling rate technology allow for more precise processing of audio signals, providing a clearer and more natural auditory experience.

Key Differences:

Latency: Traditional hearing aids have a latency of 0.6 to 8 ms, while Rehear achieves only 0.2 ms.
Frequency Range: Traditional hearing aids operate within 8 Hz to 9.64 kHz, whereas Rehear expands the range to 0-22.05 kHz, closely aligning with natural frequency ranges.
Sampling Rate: Rehear’s sampling rate reaches up to 625 kHz, compared to traditional hearing aids at 33 kHz, capturing more audio detail.
Filter Channels: Rehear utilizes 441 filter channels, compared to the 24 channels found in traditional hearing aids, allowing for more refined audio processing.

Rehear Audiology’s high sampling rate and multi-band processing technology cover the full audible frequency range of the human ear (0–22.05 kHz) in "hearing compensation adjustments." It provides up to 441 adjustable bands, significantly surpassing the traditional hearing aids' maximum of 24 bands, enabling more precise and accurate sound compensation quality.

What is Rehear’s smart AI compensation algorithm? What technology enhances users’ hearing clarity?

2024/12/24

Rehear employs a smart AI compensation algorithm that fundamentally resolves the smearing issue present in traditional multi-channel processing.
In traditional hearing aids signal adjustments across multiple channels, finer signals may overlap between frequency curves, leading to audio distortion or delays.
Rehear’s AI compensation technology effectively avoids this issue, ensuring personalized hearing compensation is completed quickly with zero distortion, taking only 150 ms.

How does RehearFit (AI Auto-REM) perform personalized audio customization?

2024/12/24

RehearFit (AI Auto-REM) rapidly measures users’ ear canal acoustic characteristics using AI algorithms,
enabling audio customization tailored to individual ear canal shapes and hearing needs.
For high-end products, hearing compensation values can be adjusted to enhance speech intelligibility and improve the overall personal hearing experience.

Is the automatic real-ear verification technology of RehearFit (AI Auto-REM) accurate?

2024/12/24

Rehear’s RehearFit (AI Auto-REM) technology has been clinically tested, showing that its measurements closely align with those of traditional professional instruments (inserting the probe 26mm-28mm deep into the ear canal).
Clinical trial results from NYCU indicate that RehearFit’s data is comparable to professional instruments, achieving performance at the 26mm-28mm recording position.

RehearFit technology provides professional-level real-ear verification results tailored to individual ear canal shapes, ensuring custom hearing compensation.

Why is RehearFit (AI Auto-REM) automatic real-ear verification necessary? How does it differ from traditional measurement methods?

2024/12/24

Traditional real-ear measurement methods rely on professional audiologists and testing instruments, making the measurement process time-consuming (usually over 30 minutes)
and requiring the measurement instrument to be deeply inserted into the eardrum (22-26mm) for testing. This not only incurs high costs but can also cause discomfort for subjects.

Rehear’s RehearFit (AI Auto-REM) technology, powered by AI algorithms, meets the needs of individual ear canals and completes automatic real-ear verification in just 15 seconds.

How does Rehear’s AI technology transform the traditional hearing aid fitting process?

2024/12/24

Traditional hearing tests typically require a professional soundproof room, taking approximately 1.5 to 2 hours
and necessitating specialized personnel to operate testing instruments while repeatedly calibrating and verifying sound compensation.
Furthermore, real-ear measurements (REM) demand a probe to be accurately inserted deep into the subject’s eardrum, complicating the process and causing discomfort.

Rehear’s three major technological innovations allow the hearing testing process to be completed accurately in just 15 minutes:

‧ANC (Active Noise Cancellation) Boothless Hearing Testing: Eliminates the reliance on traditional soundproof environments, significantly enhancing testing flexibility.
‧RehearFit Automatic Real-Ear Verification: Removes the need for manual probe insertion verification by utilizing AI algorithms to perform real-ear measurements, ensuring precise and comfortable testing.
‧AI Adapted NR: Employs AI adaptive noise patterns to adjust noise cancellation in noisy environments.
Clinically validated, this innovation fundamentally changes the fitting process of traditional hearing aids, making testing more efficient and precise.

Is the data obtained from the ANC Boothless hearing test accurate?

2024/12/24

Rehear’s ANC hearing testing technology has undergone clinical validation, demonstrating a high correlation with professional clinical hearing testing instruments.
Clinical trials conducted at Taipei Veterans General Hospital confirm that Rehear’s ANC hearing tests meet ANSI S3.6 standards, with an average error of less than 1.7 dB across frequency bands.
Pearson correlation tests exceed 0.95, indicating consistency with traditional clinical testing methods.

This technology enables the acquisition of accurate and reliable hearing threshold results.

What is ANC Boothless hearing testing technology? What equipment is needed?

2024/12/24

Simply install the testing app and use earbuds equipped with the Rehear chip solution to transform your phone into a hearing testing instrument.
This setup allows you to complete hearing threshold measurements anytime and anywhere without the need for a soundproof room, all within just 15 minutes.

Steps:
1. Open the app and conduct bilateral hearing tests.
2. Automatically activate ANC for active noise cancellation.
3. Tap the screen when you hear the beep to measure hearing thresholds

With Rehear’s AI smart hearing testing technology, you can easily obtain personal hearing threshold results that are comparable to professional tests, greatly enhancing the convenience and efficiency of the testing process.

🎉 Viva Las Vegas!

2024/12/16

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