🤖 From *WAV Speed-Listening: The 30-Day Miracle*
Daechung English, Sound Power, Speed Bible, MamaTalk — not one of the four apps had a professional developer. What it had was one person who knew what to build and why, and the AI that turned that into code. This is the record of how it happened.
In December 2021 Ossam commissioned an app from an outsourcing firm. The cost was ₩70 million — no small sum for an English teacher. But when the university-lab team that built it disbanded, updates became impossible and the app eventually became unusable. That was the price of leaving your own product’s fate in someone else’s hands. Building it yourself was not about saving money — it was about holding the fate of your own thing in your own hand.
When the AI era arrived, Ossam started small — making speed-listening videos in Python and posting them to YouTube. For the first time he did not *buy* a tool but *built* one. Next came a web app in Streamlit, and then an app for the stores. There were dead ends along the way (Flutter and others — “vibe-coding is not a cure-all”). The turning point was one line from an expert he met at an AI study group: React Native Expo. Once he could build while watching the screen in a simulator, the blockage cleared. Every step up lowered the cost and raised his control.
When hearing dulls, the first thing to smear is the consonants. With AI, Ossam built audio processing that keeps the consonants crisp, and added elements inspired by Tomatis’s high-frequency stimulation and by research on the 40 Hz gamma band (MIT, Nature 2016), folding them into a single engine — BrainHZ. Lay a different voice over that one engine and out came Daechung English, Sound Power, and Speed Bible. Build one thing properly and three came out of it. BrainHZ and Sound Power are now in trademark application, and the engine’s core technology is patent pending.
The 40 Hz element is off by default in all three apps — opt-in, for those who want it. This is so a feature whose effect cannot be asserted is not forced on every user. BrainHZ is only inspired by principles of hearing; it is not a medical device and makes no claim to prevent or treat any condition.
AI writes the code, but which road to take is often something only a person who has walked it first can tell you. Ossam asked experts for the way, and walked the rest with AI. The hands-on guide to this journey — how a non-engineer builds their own tools with AI — is in Part 3 of the book.
Individuals through the apps; companies through the engine.
Source
Reconstructed from Parts 3–4 of Seungjong Oh, *WAV Speed-Listening: The 30-Day Miracle* (Pubple, 2026). On the 40 Hz research: Iaccarino et al., Nature 540 (2016) — see [[hearing-dementia]] for the full citation.
Read the original →※ This article summarizes and restructures the key points of the source above.