Launched this week
DE Flow
Learn German through a real-time synthesizer engine
2 followers
Learn German through a real-time synthesizer engine
2 followers
DE Flow turns German grammar into sound. Every word type has its own synth voice — nouns play sawtooth at 261 Hz, verbs square wave at 440 Hz. Drag blocks into a sequencer to build sentences: correct = consonant melody, wrong = dissonance. A live oscilloscope visualizes audio in real time. Gender is neon color-coded and reinforced by distinct tones. 6 generative ambient tracks, 3 speech modes, and a Nerd Mode console with ~34 tweakable audio parameters. No ads, fully offline.
Hey PH! I built DE Flow because I wanted to experience what it feels like when grammar has a sound.
I'm a German teacher working with Taiwanese students, always looking for interesting and efficient ways of helping learners around the world. Bringing together my passion for music and languages, I worked with Claude Code to build a real-time synthesizer engine from scratch — no audio libraries, just AVAudioEngine, custom oscillators, biquad filters, and ADSR envelopes running at 44.1 kHz.
The core idea: every word type maps to a waveform and frequency. When you build a sentence in the Syntax Sequencer, you're literally composing music. Get it right and it sounds harmonic. Get it wrong and you hear tritone shifts, microtonal jitter, and noise bursts — your ears catch the mistake before your eyes do and before you see the feedback pointing to your mistake.
Some details I'm proud of:
- 9 word types, each with a unique synth voice and neon color
- Real-time oscilloscope on vocabulary cards
- 6 generative ambient tracks (3-layer synth: pad + sequencer + bass)
- 3 speech modes with DSP processing (warm filters, echo cascades)
- Nerd Mode: ~34 tweakable audio parameters with a retro control console
- Zero external dependencies — everything is built on Apple frameworks
The app is designed for Taiwanese learners studying German for university or work in Europe, but anyone at A1 level can use it. The first 3 lessons are free, and all audio features (ambient music, speech modes, nerd mode) are included at no cost.
Would love your feedback — especially from anyone into audio, synths, or language learning!