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Free classroom kit · grades 3–12

How do voice assistants hear us?

Free activities and a live demo that show students what a computer actually “hears”, why it makes mistakes, and how engineers measure them. Built by a speech AI scientist for teachers, STEM volunteers and parents.

No loginsNothing uploadedPrintableChromebook friendly
Start with the one-hour plan ↓

Activities

Use any activity on its own, or run them in order as a one-hour lesson.

Live demo · 10 min

See Your Voice

A live picture of sound. Students whistle, hiss and whisper to discover what a microphone gives a computer.

Any grade · needs a microphone · runs in the browser, records nothing
Open See Your Voice
Online or printable · 15 min

Spectrogram Detective

Read sound pictures like a computer: use clues about hiss, stripes and gaps to match eight mystery pictures to their words.

Grades 3–12 · play online with instant checking and hints, or print the 3-page PDF
Play onlineDownload PDF
Online or printable · 15 min

Be the Recognizer

Students become the voice assistant, add noise and measure their word error rate, the same metric engineers use.

Grades 4–12 · on-screen speaker cards, a noise button and automatic scoring, or print the 3-page PDF
Play onlineDownload PDF
Slides · background

How Voice Assistants Hear You

A 16-slide visual tour: sound as a wiggle, the seven AI systems inside a voice assistant, and open problems that map to STEM careers.

For teachers and classroom display · present in the browser or download the PDF
View slidesDownload PDF
Guide · 1 page

Free tools to explore speech AI

Free tools for every stage of a voice assistant, with a privacy note for each, to test real systems against your students.

Microsoft, Google, Code.org and open source · web page or one-page PDF
Open guideDownload PDF

One-hour plan: an Hour of AI, speech edition

Fits Code.org’s Hour of AI in early December, or any science or computer science class.

  1. See Your Voice (10 min). Whistle, hiss and whisper. Big idea: a computer only gets a wiggle of air pressure.
  2. Spectrogram Detective (15 min). Read sound pictures with clues. Big idea: sounds leave patterns a machine can learn.
  3. Be the Recognizer (15 min). Be the voice assistant in quiet and noise. Big idea: noise and rare words cause errors, measured as word error rate.
  4. Human vs. machine (10 min). Read the same speaker cards to Windows Live Captions or phone voice typing, paste what it wrote into the online scorer, and compare error rates. Follow your school’s technology policy.
  5. Careers (5 min). Each of the seven systems inside a voice assistant is a STEM career (slide 7). Who will fix what voice assistants still get wrong?

For teachers

  • Connects to AI4K12 Big Idea 1 (Perception) and Big Idea 4 (Natural Interaction).
  • Printouts work in black and white.
  • Students never need an account. See Your Voice runs entirely in the browser and records nothing.
  • Free to print and share for classroom use.

About

Made by Deepak Babu Piskala, IEEE Senior Member and author of Building Speech AI, who worked on speech recognition for Amazon Alexa. First shared at the IEEE STEM Summit 2026 virtual exhibit booth. A personal volunteer project; views are the author’s own, not those of his employer or IEEE.

Questions or classroom stories? Get in touch.