Opportunity
Streaks drive the daily habit, and they tend to break when people's hands and eyes are busy. Those moments add up to a large part of the day, and a voice mode also helps learners who can't easily use a screen.
The feature
- Audio lessons: normal lessons converted into guided, spoken dialogues
- Voice commands such as “next,” “repeat” and “translate again”
- Conversation practice matched to the learner's level
- XP, streaks and skill tree progress synced with standard mode
- Entry points that suggest voice mode when car mode or headphones are detected, plus streak reminders
Measuring it
Hypothesis: if learners can study during moments without a screen, daily sessions and streak retention go up. I'd run a three-arm test: control, voice-only mode, and voice plus offline download. Events would include voice_mode_started, voice_lesson_completed, voice_error_retry and streak_retained_after_voice_day, plus edge-case testing for noise, bad connectivity and accessibility settings.
About the demo
The prototype uses your browser's built-in speech features and a five-phrase Spanish lesson I wrote. It isn't affiliated with Duolingo.