expo-speech provides an API that allows you to utilize Text-to-speech functionality in your app.| Android Device | Android Emulator | iOS Device | iOS Simulator | Web |
|---|---|---|---|---|
→ expo install expo-speechIf you're installing this in a bare React Native app, you should also follow these additional installation instructions.
import * as React from 'react'; import { View, StyleSheet, Button } from 'react-native'; import * as Speech from 'expo-speech'; export default function App() { const speak = () => { const thingToSay = '1'; Speech.speak(thingToSay); }; return ( <View style={styles.container}> <Button title="Press to hear some words" onPress={speak} /> </View> ); } %%placeholder-start%%const styles = StyleSheet.create({ ... }); %%placeholder-end%%const styles = StyleSheet.create({ container: { flex: 1, justifyContent: 'center', backgroundColor: '#ecf0f1', padding: 8, }, });
import * as Speech from 'expo-speech';
Type: number
Maximum possible text length acceptable by Speech.speak() method. It is platform-dependent.
On iOS, this returns Number.MAX_VALUE.
Returns list of all available voices.
List of Voice objects.
Determine whether the Text-to-speech utility is currently speaking. Will return true if speaker
is paused.
Promise<boolean>Returns a Promise that fulfils with a boolean, true if speaking, false if not.
Resumes speaking previously paused speech or does nothing if there's none. This method is not available on Android.
Promise<void>| Name | Type | Description |
|---|---|---|
| text | string | The text to be spoken. Cannot be longer than Speech.maxSpeechInputLength. |
| options (optional) | SpeechOptions | A SpeechOptions object.Default: {} |
Speak out loud the text given options. Calling this when another text is being spoken adds an utterance to queue.
void| Name | Type | Description |
|---|---|---|
| this | SpeechSynthesisUtterance | - |
| ev | SpeechSynthesisEvent | - |
| Name | Type | Description |
|---|---|---|
| _voiceIndex (optional) | number | - |
| language (optional) | string | The code of a language that should be used to read the text, refer to IETF BCP 47 to see
valid codes. |
| onBoundary (optional) | SpeechEventCallback | null | - |
| onMark (optional) | SpeechEventCallback | null | - |
| onPause (optional) | SpeechEventCallback | null | - |
| onResume (optional) | SpeechEventCallback | null | - |
| pitch (optional) | number | Pitch of the voice to speak text. 1.0 is the normal pitch. |
| rate (optional) | number | Rate of the voice to speak text. 1.0 is the normal rate. |
| voice (optional) | string | Voice identifier. |
| volume (optional) | number | Only for: Web
Volume of the voice to speak text. A number between 0.0 (muted) and 1.0 (max volume)Default: 1.0 |
| onDone (optional) | () => void | A callback that is invoked when speaking finishes. |
| onError (optional) | (error: Error) => void | Only for: Android
A callback that is invoked when an error occurred while speaking. |
| onStart (optional) | () => void | A callback that is invoked when speaking starts. |
| onStopped (optional) | () => void | A callback that is invoked when speaking is stopped by calling Speech.stop(). |
Object describing the available voices on the device.
| Name | Type | Description |
|---|---|---|
| identifier | string | Voice unique identifier. |
| language | string | Voice language. |
| name | string | Voice name. |
| quality | VoiceQuality | Voice quality. |
Voice extended by:
| Name | Type | Description |
|---|---|---|
| isDefault | boolean | - |
| localService | boolean | - |
| name | string | - |
| voiceURI | string | - |
Enum representing the voice quality.
VoiceQuality.Default ＝ "Default"VoiceQuality.Enhanced ＝ "Enhanced"