How to Build a Pronunciation Guide App with AI Voice

Why a Pronunciation Guide App?

When you’re learning a new language, the hardest part is often hearing the correct sounds and reproducing them. Text‑to‑speech (TTS) lets you turn written words into spoken audio, and when you combine that with voice‑cloning you can create a “native‑speaker” experience for any word or phrase.

A pronunciation guide app that uses AI voice can:

• Give instant feedback – users hear exactly how a word should sound.
• Scale to any vocabulary – no need to record thousands of samples manually.
• Support multiple accents – clone a voice from a single recording and let the AI generate any word in that accent.

Below, I walk you through building a simple, developer‑friendly pronunciation guide app that leverages the ElevenLabs TTS platform.

---

1. Pick the right TTS engine

ElevenLabs provides a cloud‑based TTS API with high‑fidelity, natural‑sounding voices. It also supports voice cloning from a few minutes of audio, which is perfect for our pronunciation app.

You can sign up for a free tier and get an API key via the affiliate link:

https://try.elevenlabs.io/kr07zfuqn1bp

Tip: Keep your API key out of the client‑side code. Store it in environment variables on your backend.

---

2. Set up the backend

For this tutorial I’ll use Python + FastAPI because it’s lightweight and has great async support. Feel free to swap it out for Node.js, Go, or whatever you’re comfortable with.

# Create a virtual environment
python -m venv venv
source venv/bin/activate

# Install dependencies
pip install fastapi uvicorn httpx python-dotenv

Create a .env file with your ElevenLabs key:

ELEVENLABS_API_KEY=sk_XXXXXXXXXXXXXXXX

Now write main.py:

import os
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import httpx
from dotenv import load_dotenv

load_dotenv()
API_KEY = os.getenv("ELEVENLABS_API_KEY")
BASE_URL = "https://api.elevenlabs.io/v1"

app = FastAPI()

class SpeakRequest(BaseModel):
    text: str
    voice_id: str  # Optional: specify a voice ID, e.g., "eleven_monolingual_v1"

@app.post("/speak")
async def speak(request: SpeakRequest):
    url = f"{BASE_URL}/text-to-speech/{request.voice_id}"
    headers = {
        "xi-api-key": API_KEY,
        "Content-Type": "application/json"
    }
    payload = {
        "text": request.text,
        "voice_settings": {
            "stability": 0.5,
            "similarity_boost": 0.75
        }
    }
    async with httpx.AsyncClient() as client:
        resp = await client.post(url, json=payload, headers=headers)
        if resp.status_code != 200:
            raise HTTPException(status_code=resp.status_code, detail=resp.text)
        # ElevenLabs returns audio bytes directly
        return Response(content=resp.content, media_type="audio/mpeg")

Run the server:

uvicorn main:app --reload

You now have a /speak endpoint that accepts text and a voice ID, and returns a spoken MP3.

---

3. Cloning a voice

To give users the ability to “clone” a voice (e.g., a native speaker of Spanish), you’ll need to upload an audio sample. ElevenLabs accepts a WAV or MP3 file and returns a voice_id you can reuse.

# curl example
curl -X POST "https://api.elevenlabs.io/v1/voices" \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F "name=MySpanishSpeaker" \
  -F "file=@sample.wav"

The response will contain a voice_id. Store this ID in your database linked to the user who uploaded the sample.

---

4. Building the front‑end

A minimal React app that talks to the FastAPI backend is enough to demo the concept.

npx create-react-app pronunciation-app
cd pronunciation-app
npm install axios

src/App.js:

import { useState } from 'react';
import axios from 'axios';

function App() {
  const [text, setText] = useState('');
  const [audioURL, setAudioURL] = useState(null);
  const voiceId = 'eleven_monolingual_v1'; // Replace with user‑cloned ID

  const speak = async () => {
    const resp = await axios.post('/speak', { text, voice_id: voiceId }, {
      responseType: 'blob', // Important to get binary data
    });
    const url = URL.createObjectURL(resp.data);
    setAudioURL(url);
  };

  return (
    <div style={{ padding: 20 }}>
      <h2>Pronunciation Guide</h2>
      <textarea
        rows={3}
        value={text}
        onChange={e => setText(e.target.value)}
        placeholder="Type a word or sentence..."
        style={{ width: '100%' }}
      />
      <button onClick={speak}>Listen</button>

      {audioURL && (
        <div style={{ marginTop: 20 }}>
          <audio controls src={audioURL} />
        </div>
      )}
    </div>
  );
}

export default App;

Proxying API calls

In package.json add:

"proxy": "http://localhost:8000"

Now you can run npm start and test the UI.

---

5. Adding pronunciation accuracy checks

For a richer experience, you can compare the spoken word from the user (using Web Speech API or a microphone upload) against the AI‑generated audio. Use libraries like audioconcat or librosa to compute similarity scores. This step is optional but can turn a simple app into an interactive learning tool.

---

6. Deploying

• Backend – Deploy the FastAPI app to Fly.io, Render, or any cloud provider that supports ASGI.
• Frontend – Host on Vercel, Netlify, or your own static hosting.

Make sure to add your ElevenLabs API key to the environment variables of your deployment platform.

---

7. Security & Rate limits

ElevenLabs enforces rate limits on the free tier (e.g., 5 k characters per minute). Keep that in mind if you allow users to type long passages. You can mitigate by:

1. Limiting the text length per request.
2. Queueing requests on the backend.
3. Prompting users to upgrade to a paid plan for heavy usage.

---

8. Next‑level ideas

Feature	Why it matters	How to implement
Accent comparison	Show users how close they are to the native accent	Use a similarity metric on waveform data
Progress tracking	Gamify learning	Store user attempts in a database, reward streaks
Multi‑language support	Reach a wider audience	Switch voice IDs per language, add language selector

---

Conclusion

With just a few lines of code and a single API key from ElevenLabs, you can turn a simple text input into a high‑quality pronunciation guide. The combination of TTS and voice cloning opens up a world of possibilities for language learning, accessibility tools, and even interactive games.

Ready to build? Grab your ElevenLabs API key now and start experimenting.

https://try.elevenlabs.io/kr07zfuqn1bp