@techoptio/react-native-live-pitch-detection

Live pitch detection (frequency, note and octave) from device microphone for React Native.

This package was heavily inspired by, but not a direct fork of, https://github.com/rnheroes/react-native-pitchy.

This package uses Turbo Modules and is only compatible with the new architecture.

Installation

npm install @techoptio/react-native-live-pitch-detection

iOS

For iOS, you'll need to add microphone permission to your Info.plist:

<key>NSMicrophoneUsageDescription</key>
<string>This app needs microphone access to detect pitch.</string>

Android

For Android, you'll need to add microphone permission to your AndroidManifest.xml:

<uses-permission android:name="android.permission.RECORD_AUDIO" />

Usage

Important: This library assumes microphone permissions have already been requested and granted before calling startListening(). Make sure to request permissions using a library like react-native-permissions before using this library.

import PitchDetection from '@techoptio/react-native-live-pitch-detection';
import { request, PERMISSIONS, RESULTS } from 'react-native-permissions';
import { Platform } from 'react-native';

// Request microphone permission first
const permission = Platform.OS === 'ios'
  ? PERMISSIONS.IOS.MICROPHONE
  : PERMISSIONS.ANDROID.RECORD_AUDIO;

const result = await request(permission);

if (result === RESULTS.GRANTED) {
  // Configure options (optional) - should be called while not listening
  PitchDetection.setOptions({
    bufferSize: 4096,        // Audio buffer size (default: 4096)
    minVolume: -20.0,        // Minimum volume threshold in dB (default: -20.0)
    updateIntervalMs: 100,   // Update interval in milliseconds (default: 100)
    a4Frequency: 440,        // A4 note frequency in Hz (default: 440)
  });

  // Start listening
  await PitchDetection.startListening();

  // Add listener for pitch events
  const subscription = PitchDetection.addListener((event) => {
    console.log('Frequency:', event.frequency);
    console.log('Note:', event.note); // e.g., "C4", "A#3", etc.
  });

  // Stop listening when done
  await PitchDetection.stopListening();
  subscription.remove();
}

API

Methods

setOptions(options: Options)

Configure the pitch detection settings. This method is optional, as all parameters have defaults. However, if you want to customize the settings, call this method while not listening (i.e., before startListening() or after stopListening()), otherwise all parameters may not be applied until the next listening session.

Parameters:

• options.bufferSize?: number - Audio buffer size (default: 4096)
• options.minVolume?: number - Minimum volume threshold in dB (default: -20.0)
• options.updateIntervalMs?: number - Update interval in milliseconds (default: 100)
• options.a4Frequency?: number - A4 note frequency in Hz (default: 440)

startListening(): Promise<void>

Starts listening to the microphone for pitch detection.

Note: Ensure microphone permissions have been requested and granted before calling this method.

stopListening(): Promise<void>

Stops listening to the microphone.

addListener(callback: (event: PitchEvent) => void): EventSubscription

Adds a listener for pitch detection events. Returns an EventSubscription that should be removed when no longer needed.

Event:

type PitchEvent = {
  frequency: number;  // Detected frequency in Hz
  note: string;       // Musical note (e.g., "C4", "A#3", "-" if no note detected)
};

isListening(): boolean

Returns true if currently listening, false otherwise.

Types

type Options = {
  bufferSize?: number;
  minVolume?: number;
  updateIntervalMs?: number;
  a4Frequency?: number;
};

type PitchEvent = {
  frequency: number;
  note: string;
};

Example

Check out the example app for a complete working implementation.

Contributing

• Development workflow
• Sending a pull request
• Code of conduct

License

MIT

Made with create-react-native-library