For everyone who values their hearing
Measure your hearing age and train your ears in one app — protect the high-frequency hearing that fades with age.

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App Store
Find your hearing age from the moment a slowly rising tone becomes clearly audible.
Record the top frequency you can hear as an objective number — retest a month later and compare the change.
High frequencies are the first to fade with age. Speed-listening training helps you keep and sharpen them.
Hearing training and English listening in one app — as your ears get younger, English gets easier to catch.
With age, the high frequencies fade first. But the ear isn’t just for hearing — it’s the gateway to your brain.
Tomatis theory — frequencies above 5kHz are “food for the brain,” feeding focus and alertness.
A 3-step loop that starts with a number and ends with a number
Test your hearing age, audible frequency, and English listening in minutes to set your own baseline.
Listen to Korean audio and repeat it, stepping up from 2× to 5×, while AI scores your pronunciation.
Measure again after training — compare the old you and the new you, number to number.
We kept the high notes that MP3 throws away
Compression cuts off frequencies above roughly 16kHz — exactly the high notes that hearing training needs.
Lossless WAV audio plus BrainHZ high frequencies delivers the rarely-stimulated high band clearly.
A user in their mid-60s first measured a hearing age in the 70s and had to keep the TV nearly maxed out (volume 20). After a month of 30–60 minutes of Korean speed-listening a day, they measured a hearing age in the 20s and turned the TV down to 7.
* Based on subjective, self-measured values; results vary from person to person.
As you get used to Korean speed-listening, your brain processes faster and your English-listening ears open up too. Hearing training and English listening in one app.
Don’t want to install an app? Measure and train right away in your phone or desktop browser.
Find your hearing age from a slowly rising tone
Measure on the web →See the top frequency you can hear as a number
Measure on the web →Check your English listening with speed dictation
Measure on the web →📱 Screen preview




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Every claim cites a verifiable primary study.
The Lancet Commission (2020·2024): ~40% of dementia is preventable, and hearing loss is the single largest modifiable risk factor (7–8%). In the ACHIEVE RCT, hearing intervention cut cognitive decline by 48% in high-risk adults. → This is why hearing care matters.
Source: Lancet 396(2020)·404(2024) · ACHIEVE, Lancet 402(2023) · WHO 2021
French ENT Dr. Tomatis: the ear isn't just for hearing — it charges ~30% of the brain's energy, and higher frequencies deliver more of that alertness energy.
Source: Tomatis A., The Conscious Ear (1996)
MIT Iaccarino (Nature 2016): 40Hz stimulation cleared Alzheimer's proteins (Aβ/Tau) by 37–53% and boosted microglia, neuroplasticity, and neural synchrony. BrainHz applies 40Hz modulation to its audio.
Source: Iaccarino et al., Nature 540:230-235 (2016)
Merzenich (UCSF): the adult and aging brain can rewire. An aged, dulled auditory cortex can be re-sharpened with repeated auditory training.
Source: Merzenich M., UCSF / Doidge, The Brain That Changes Itself
Delivers sound through bone straight to the cochlea, bypassing the air–eardrum path. Less ear-canal fatigue — good for seniors' long training and bedtime playback.
Source: Stenfelt S. / Shokz (AfterShokz)
A 1/f-spectrum natural noise. Northwestern (2017): pink noise during deep sleep enhanced slow-wave sleep and memory consolidation.
Source: Papalambros et al., Front. Hum. Neurosci. (2017)
2–5x compressed speech gives the auditory cortex a harder-than-normal task, forcing neural reorganization. Start with familiar Korean to raise processing speed.
Source: Speed Listening project / Merzenich (training difficulty)
A training-grade sound engine: lossless WAV, restored 16–24kHz highs, and 40Hz modulation combined — keeping the high frequencies MP3 throws away.
Source: BrainHz DSP spec
⚠️ This is educational research citation and does not guarantee prevention or treatment of any disease.