# LiveKit React Native Microphone Bug Report ## Bug Description The LiveKit React Native SDK v2.7.6 fails to publish microphone tracks due to a

TypeError: Cannot read property ‘toLowerCase’ of undefined

error. ## Environment - SDK Version: @livekit/react-native v2.7.6 - Platform: iOS (iPhone) - React Native: Latest - Device: iPhone (any model) ## Error Details

TypeError: Cannot read property ‘toLowerCase’ of undefined

This error occurs when: 1. Calling

room.localParticipant.setMicrophoneEnabled(true)

2. Calling

room.localParticipant.publishTrack(audioTrack)

3. Using

audio={true}

prop on LiveKitRoom component ## Minimal Reproduction Code ### 1. App.tsx (Main App)

tsx
import React from ‘react’;
import { registerGlobals } from ‘@livekit/react-native’;

_// Register globals first_
registerGlobals();

export default function App() {
  return <LiveKitTest />;
}

### 2. LiveKitTest.tsx (Minimal Test Component)

tsx
import React, { useState, useEffect } from ‘react’;
import { View, Text, Button, Alert } from ‘react-native’;
import { LiveKitRoom, AudioSession } from ‘@livekit/react-native’;
import { Room } from ‘livekit-client’;

const LIVEKIT_URL = ‘<wss://your-livekit-server.com>’;
const TOKEN = ‘your-livekit-token’;

function LiveKitTest() {
  const [isConnected, setIsConnected] = useState(false);
  const [room, setRoom] = useState<Room | null>(null);

  useEffect(() => {
    _// Start audio session_
    AudioSession.startAudioSession();
    return () => AudioSession.stopAudioSession();
  }, []);

  const testMicrophone = async () => {
    if (!room) return;

    try {
      console.log(‘:microphone: Testing setMicrophoneEnabled...’);
      await room.localParticipant.setMicrophoneEnabled(true);
      console.log(‘:white_check_mark: setMicrophoneEnabled succeeded’);
    } catch (error) {
      console.error(‘:x: setMicrophoneEnabled failed:’, error);
      Alert.alert(‘Error’, `setMicrophoneEnabled failed: ${error}`);
    }
  };

  const testPublishTrack = async () => {
    if (!room) return;

    try {
      console.log(‘:microphone: Testing publishTrack...’);
      const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
      const audioTrack = stream.getAudioTracks()[0];

      await room.localParticipant.publishTrack(audioTrack, {
        name: ‘microphone’,
        source: ‘microphone’,
      });
      console.log(‘:white_check_mark: publishTrack succeeded’);
    } catch (error) {
      console.error(‘:x: publishTrack failed:’, error);
      Alert.alert(‘Error’, `publishTrack failed: ${error}`);
    }
  };

  return (
    <View _style_={{ flex: 1, padding: 20, justifyContent: ‘center’ }}>
      <Text _style_={{ fontSize: 18, marginBottom: 20 }}>
        LiveKit React Native Microphone Test
      </Text>

      <LiveKitRoom
        _serverUrl_={LIVEKIT_URL}
        _token_={TOKEN}
        _connect_={true}
        _audio_={true}
        _onConnected_={() => {
          console.log(‘:white_check_mark: Connected to LiveKit’);
          setIsConnected(true);
        }}
        _onDisconnected_={() => {
          console.log(‘:x: Disconnected from LiveKit’);
          setIsConnected(false);
        }}
      >
        <View _style_={{ flex: 1, justifyContent: ‘center’ }}>
          <Text>Connection Status: {isConnected ? ‘Connected’ : ‘Disconnected’}</Text>

          <Button
            _title_=“Test setMicrophoneEnabled”
            _onPress_={testMicrophone}
            _disabled_={!isConnected}
          />

          <Button
            _title_=“Test publishTrack”
            _onPress_={testPublishTrack}
            _disabled_={!isConnected}
          />
        </View>
      </LiveKitRoom>
    </View>
  );
}

export default LiveKitTest;

### 3. package.json Dependencies

json
{
  “dependencies”: {
    “@livekit/react-native”: “^2.7.6”,
    “@livekit/react-native-webrtc”: “^125.0.11”,
    “livekit-client”: “^1.15.0”,
    “react-native”: “0.72.0”
  }
}

### 4. iOS Info.plist (Required Permissions)

xml
<key>NSMicrophoneUsageDescription</key>
<string>This app needs microphone access for voice chat</string>

## Steps to Reproduce 1. Install dependencies:

bash
   npm install @livekit/react-native@2.7.6 @livekit/react-native-webrtc@125.0.11 livekit-client@1.15.0

2. Set up iOS: - Add microphone permission to Info.plist - Run

cd ios && pod install

3. Get LiveKit token: - Replace

LIVEKIT_URL

and

TOKEN

with your LiveKit server details 4. Run the app:

bash
   npx react-native run-ios

5. Test the bug: - Connect to LiveKit room - Press “Test setMicrophoneEnabled” button - Press “Test publishTrack” button - Both will fail with the toLowerCase error ## Expected Behavior -

setMicrophoneEnabled(true)

should enable and publish microphone -

publishTrack(audioTrack)

should publish the audio track -

audio={true}

prop should auto-publish microphone ## Actual Behavior - All methods fail with

TypeError: Cannot read property ‘toLowerCase’ of undefined

- No microphone tracks are published - Audio functionality is completely broken ## Debug Information The error occurs in the LiveKit SDK when it tries to process track metadata or device labels. The undefined value being passed to

toLowerCase()

suggests the SDK is not handling track properties correctly. ## Workarounds Attempted 1. ✅ Added AudioSession initialization 2. ❌ Direct MediaStream API - same error 3. ❌ LocalAudioTrack creation - same error 4. ❌ createLocalAudioTrack helper - same error 5. ❌ audio={true} prop - auto-publish fails with same error ## Impact This bug completely prevents microphone usage in LiveKit React Native apps, making voice chat impossible. ## Request Please investigate and fix the

toLowerCase

error in the track publication process. This appears to be a regression in v2.7.6 as it affects all microphone-related functionality.

Thanks for reaching out, Sumiya. I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.

Thank you for your suggestions. I’ve implemented all the recommended fixes, but the

toLowerCase

error persists. Here’s what I’ve done and the current status: ## ✅ Implemented Your Suggestions ### 1. Microphone Permissions - ✅ Already Configured iOS Info.plist (already present):

xml
<key>NSMicrophoneUsageDescription</key>
<string>This app needs access to the microphone for voice conversation practice and speech recognition features.</string>

Android AndroidManifest.xml (already present):

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

### 2. Audio Session Configuration - ✅ Already Implemented iOS: AudioSession is properly initialized in the component:

tsx
useEffect(() => {
  const startAudioSession = async () => {
    try {
      console.log(':loud_sound: Starting audio session...');
      await AudioSession.startAudioSession();
      console.log(':white_check_mark: Audio session started');
    } catch (error) {
      console.error(':x: Failed to start audio session:', error);
    }
  };
  
  startAudioSession();
  return () => AudioSession.stopAudioSession();
}, []);

Android: Need to add LiveKit setup to MainApplication.kt:

kotlin
import com.livekit.reactnative.LiveKitReactNative
import com.livekit.reactnative.audio.AudioType

class MainApplication : Application(), ReactApplication {
  override fun onCreate() {
    super.onCreate()
    // Add this line before other RN initialization
    LiveKitReactNative.setup(this, AudioType.CommunicationAudioType())
    // ... rest of onCreate
  }
}

### 3. Track Publication Code - ✅ Already Using Correct Method

tsx
await room.localParticipant.setMicrophoneEnabled(true);

## ❌ The Bug Persists Despite All Fixes Even with all your suggestions implemented, the error still occurs:

INFO  publishing track {"enabled": true, "kind": "audio", "muted": false, "pID": "PA_xxx", "participant": "xxx", "room": "xxx", "roomID": "", "source": "microphone", "streamID": "xxx", "streamTrackID": "xxx", "trackID": undefined}
WARN  [TypeError: Cannot read property 'toLowerCase' of undefined]

## 🔍 Additional Debugging Information ### The Error Occurs In Multiple Contexts: 1. setMicrophoneEnabled(true) - fails with toLowerCase error 2. publishTrack(audioTrack) - fails with same error 3. audio={true} prop on LiveKitRoom - auto-publish fails with same error 4. createLocalAudioTrack() - fails with same error ### Track Publication Status:

javascript
// After connection, trackPublications array is empty:
trackPublications: []
// No microphone track is successfully published

### Permission Status: - ✅ Microphone permissions are granted - ✅ AudioSession is started successfully - ✅ Room connects successfully - ✅ Agent joins the room - ❌ Microphone track publication fails with toLowerCase error ## 🐛 This Appears to be a SDK Bug The error suggests the LiveKit SDK is trying to call

toLowerCase()

on an undefined value during track publication. This happens regardless of: - How the track is created (MediaStream, LocalAudioTrack, etc.) - How it’s published (setMicrophoneEnabled, publishTrack, auto-publish) - Platform configuration (iOS/Android) - Permission status ## 📋 Request for Further Investigation Could you please: 1. Check if this is a known issue in v2.7.6 2. Test the minimal reproduction code I provided in the bug report 3. Verify if this is a regression from earlier versions 4. Provide a workaround if the bug can’t be fixed immediately

I don't have the answer you're looking for. You could also try asking your question: • in one of the other Slack channels or • to https://deepwiki.com/livekit/livekit_composite which is trained on all LiveKit source code If you find the answer, please post it here to help others!