🎧 What if someone could secretly hear the answers through a tiny wireless earbud during an online test? That's exactly what a groundbreaking new "ear scanning" technology aims to prevent.
The Duolingo English Test, accepted by over 6,000 educational institutions worldwide, has made ear scanning mandatory for all test-takers. Using machine learning to detect hidden wireless earbuds, this innovation represents a new frontier in online exam security. Here's how it works.
Why "Ear Scanning" Became Necessary
As online testing has become more common, cheating methods have grown increasingly sophisticated. One major concern is the use of wireless earbuds for cheating. Modern wireless earbuds have become so miniaturized that they're virtually invisible to the naked eye. Test-takers have been caught hiding tiny devices deep in their ear canals to receive answers from accomplices outside.
In Japan, the 2022 Common University Entrance Test saw a major scandal when test questions were leaked via smartphone during the exam. Korean universities have also reported widespread cheating through phone calls and social media during online exams. For test administrators worldwide, preventing such cheating has become an urgent priority.
How Duolingo's "Ear Scan" Works
The Duolingo English Test (DET) has introduced "Ear Scan" technology that requires all test-takers to scan both ears using their smartphone camera before the exam begins.
The scanning process is straightforward. Test-takers position their smartphone camera toward one ear, first from a distance, then close up. This far-and-near scanning is repeated for both ears. The entire process takes just one to two minutes.
During this brief procedure, machine learning algorithms analyze the images to detect whether earbuds or audio-receiving devices are hidden inside the ear canal. The system works across all smartphone models, ensuring consistent security regardless of what device test-takers use.
Ear Biometrics: As Unique as Fingerprints
Here's a fascinating fact: the shape of your ear is as unique as your fingerprint, making it a powerful tool for personal identification.
Research by NEC, published in 2016, demonstrated that ear-based biometric authentication can achieve over 99% accuracy. Not only the outer ear shape but also the ear canal's structure differs from person to person—even identical twins have distinguishable ears.
Moreover, ears remain remarkably stable between ages 8 and 70, making them ideal for long-term biometric verification. Since the COVID-19 pandemic made face recognition difficult due to mask-wearing, ear biometrics has gained attention as a next-generation identification technology.
However, Duolingo's Ear Scan isn't designed for identity verification—its sole purpose is detecting hidden devices inside the ear.
Multi-Layered Security for Online Testing
The DET combines Ear Scan with multiple other security measures for a comprehensive defense system.
First, there's a dual AI-human proctoring system. AI analyzes test session videos in real-time to flag suspicious behavior, which human proctors then review. Eye movement patterns and unusual sounds are among the detection targets.
Second, the test uses an adaptive format. Drawing from a database of over 45,000 questions, the system adjusts question content in real-time based on each test-taker's responses. No two tests are identical, dramatically reducing the risk of leaked questions or pre-planned cheating.
Additionally, a secondary camera requirement and room scanning (360-degree room check) ensure the entire testing environment is monitored. Test-takers must set up their camera to capture their keyboard, screen, and upper body.
Adoption in Japan and Impact on University Admissions
Currently, 17 universities and educational institutions in Japan accept DET scores for admissions. Globally, over 90% of the top 100 universities in the US News Ranking have adopted the test, establishing DET as a viable third option alongside TOEFL and IELTS.
What sets DET apart is its accessibility: the $70 USD fee (approximately half that of TOEFL or IELTS), 24/7 at-home availability, and 48-hour score turnaround offer conveniences traditional English proficiency tests can't match.
Japan's Ministry of Education has also taken notice. In November 2025, a working group on comprehensive English assessment for university admissions discussed anti-cheating measures across various testing organizations, signaling that online test integrity is becoming a national policy concern.
The Ongoing Technology vs. Cheating Arms Race
The introduction of Ear Scan is just one example of how security measures must evolve alongside technology. Duolingo has announced that it's developing detection systems for deepfakes and ChatGPT-assisted cheating.
Online testing offers tremendous benefits—providing fair testing opportunities regardless of geographic or economic circumstances. But maintaining that fairness requires equally advanced security technology.
The "ear scanning" solution may seem unusual at first, but it represents the cutting edge of how digital-age test administration is tackling integrity challenges head-on.
In Japan, there's ongoing debate about preventing cheating in online exams. What about in your country? How are online tests and biometric security measures being implemented? We'd love to hear about the situation where you live!
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Reactions in Japan
Ear scanning is impressive, but honestly, it just adds more hassle for people taking the test legitimately. It feels like honest test-takers are being inconvenienced because of cheaters.
Using machine learning to check inside ears? Technology really is advancing. If it improves online test reliability, I'm all for it. Hope TOEFL adopts this too.
I usually recommend Eiken or TOEIC to students, but Duolingo seems like a viable option now. If their anti-cheating measures are solid, I feel confident recommending it.
Ear scanning means collecting biometric data, right? I'm worried about how that data is stored and used. Need to check the privacy policy carefully.
I took the Duolingo test last year and the room scan and second camera setup were already a hassle. Adding ear scanning makes preparation even more complicated.
My university abroad accepted Duolingo, so I took it—cheaper and easier than TOEFL. Hope stronger security helps it gain more recognition.
Ear shapes are apparently as unique as fingerprints. Maybe we'll have wearable earphone devices for constant authentication in the future. Duolingo might be pioneering this.
I heard SPI and other web tests have lots of cheating too. I hope this kind of technology spreads. I don't want a world where honest people lose out.
What about people who use hearing aids? Can they apply in advance for accommodation? I hope they consider accessibility.
Improving online test reliability is crucial for us too. It was discussed at the MEXT working group. We'll be watching developments closely.
Even with ear scanning, we're in an age where AI can generate answers. It's just an endless cat-and-mouse game. Maybe it's time to rethink how tests work fundamentally?
Duolingo's strength is the adaptive format—no identical tests. Combined with ear scanning, their security is getting quite robust.
My child is studying abroad next year and will take Duolingo. Home testing is convenient, but the setup seems complicated—parents might need to help.
Diversifying biometrics is a good trend. Multimodal authentication combining face, ear, voiceprint, and gait will become mainstream.
This reminds me of the 2022 Common Test leak incident. I've been skeptical of online tests since then, but with measures like this, I might reconsider.
This is great! I'm taking Duolingo next month and I hated the idea of being evaluated alongside cheaters. If this keeps things fair, I'm all for it.
Cheating on online tests is a huge problem in China. If this technology spreads, students who study seriously will finally get the recognition they deserve.
Many students in India use Duolingo for study abroad. Ear scanning feels a bit invasive, but if it maintains test integrity, I can accept it.
Honestly, I'm concerned about privacy. Where is this biometric data stored and who has access? Duolingo needs to be more transparent about this.
I live in rural Mexico and it takes hours to reach a TOEFL test center. If Duolingo lets me test from home with solid security, it's the best option.
In Egypt, many students can't afford to take expensive tests multiple times. Duolingo's low cost combined with high security is a beacon of hope for developing country students.
As a German university staff member, online test cheating is a headache for admissions. We welcome such technological innovations. We need trustworthy scores.
Technically interesting, but what about people with long hair or earrings? I'm curious how they handle edge cases.
IELTS dominates in the UK, but Duolingo's security measures are impressive. I wish more universities would accept it.
I'm applying to US universities from Brazil. Ear scanning sounds weird, but considering TOEFL's high cost and few test centers, Duolingo is attractive.
In Russia, proxy test-taking services have become a problem. If this technology spreads, their business model will collapse. Good thing.
In Korea, cheating via SNS during online exams became a social issue. Other test administrators should learn from Duolingo's multi-layered security.
Many people in the UAE aim to study abroad. Duolingo's affordable pricing combined with security is great news for Middle Eastern students.
As a Taiwanese engineer, I'm interested in this implementation. How was the ML algorithm trained to detect earbuds? Fascinating technology.
Working at a Polish university, the reliability of English proficiency certificates from international students is always a challenge. I hope such innovations restore trust.