SHADOWCAST AILanguage Laboratory
ShadowCast = Shadow + Broadcast
Learn to speak like real YouTubers, not robots.
Transform any YouTube video into authentic CEFR shadowing drills. Loop real-human vocal slices, record your voice, and get Gemini 3.8 Flash pitch contour and IPA phonetic grading in real time.
Filter Level:
Or try curated soundbites:
01
Ingest & CEFR Slicing
Gemini 3.8 Flash extracts natural 3–7s breathing phrases from authentic YouTube audio, classifying them from A2 Elementary to C1 Advanced colloquial fast-speech.
Zero robotic synthetic voices. 100% human cadence.
02
A-B Precision Loop
Synchronized YouTube player loops the exact millisecond soundbite. Read the target IPA transcription, discover linked contractions (e.g. “gonna”, “outta”), and internalize native pitch rhythm.
Variable speed control: 0.75x • 1.0x • 1.25x
03
Multimodal Acoustic Match
Record your voice. Gemini compares your acoustic pitch contour against the original YouTuber, highlighting word-by-word phonetic accuracy and advising on native intonation glides.
0-100% pronunciation score & pitch contour visual
Acoustic Demonstration
YouTuber Target vs Your Vocal Shadow
YouTuber Pitch Target
User Mic Contour
[00:14.5] “The moment you start...”[00:17.2] “...second-guessing yourself...”[00:19.8] “...senses hesitation.”
Acoustic Match: 94%•CEFR B2 Upper Intermediate
Practice This Clip Live in Console →