From 7ecc9664c16b49a5126184ce04552886385a60ba Mon Sep 17 00:00:00 2001
From: Felix <felix@mac-studio.tail348b44.ts.net>
Date: Thu, 6 Aug 2026 14:21:02 +0300
Subject: [PATCH] fix(ios): enable voice-processing I/O for voiceChat/videoChat
 session modes
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AVAudioSession mode voiceChat configures routing and EQ but does not enable
echo cancellation — that requires setVoiceProcessingEnabled on the engine's
input node. Full-duplex apps (VoIP, realtime voice agents) currently get raw
speaker echo in the mic stream, so server-side VAD self-triggers and agents
interrupt their own playback.

Enable Apple's voice-processing I/O (AEC + noise suppression + AGC) on the
system input node whenever the desired session mode is voiceChat or videoChat,
before the input connection format is read (voice processing changes the
hardware format) and only while the engine is stopped. Modes are synced both
ways so leaving voice-chat mode disables it again.
---
 .../ios/audioapi/ios/system/AudioEngine.mm    | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/packages/react-native-audio-api/ios/audioapi/ios/system/AudioEngine.mm b/packages/react-native-audio-api/ios/audioapi/ios/system/AudioEngine.mm
index d91ed60f9..b9c289984 100644
--- a/packages/react-native-audio-api/ios/audioapi/ios/system/AudioEngine.mm
+++ b/packages/react-native-audio-api/ios/audioapi/ios/system/AudioEngine.mm
@@ -38,6 +38,7 @@ - (BOOL)hasTrackedGraph;
 - (AVAudioFormat *)currentInputConnectionFormat;
 - (void)materializeSourceNodeWithId:(NSString *)sourceNodeId;
 - (BOOL)materializeInputNodeIfNeeded;
+- (void)syncVoiceProcessingWithSessionMode;
 - (void)materializeTrackedNodesIfNeeded;
 
 - (AVAudioFormat *)liveInputFormat;
@@ -186,6 +187,8 @@ - (BOOL)materializeInputNodeIfNeeded
     return YES;
   }
 
+  [self syncVoiceProcessingWithSessionMode];
+
   AVAudioFormat *inputFormat = [self currentInputConnectionFormat];
 
   if (inputFormat == nil) {
@@ -199,6 +202,33 @@ - (BOOL)materializeInputNodeIfNeeded
   return YES;
 }
 
+// Voice-chat session modes imply Apple's voice-processing I/O (echo
+// cancellation, noise suppression, AGC). Without it, speaker output loops back
+// into the microphone — full-duplex apps (VoIP, voice agents) hear themselves
+// and speech detection self-triggers. Must run before the input format is read
+// (voice processing changes the hardware format) and while the engine is
+// stopped.
+- (void)syncVoiceProcessingWithSessionMode
+{
+  AVAudioSessionMode mode = self.sessionManager.desiredMode;
+  BOOL wantsVoiceProcessing = [mode isEqualToString:AVAudioSessionModeVoiceChat] ||
+      [mode isEqualToString:AVAudioSessionModeVideoChat];
+
+  AVAudioInputNode *systemInputNode = self.audioEngine.inputNode;
+  if (systemInputNode.isVoiceProcessingEnabled == wantsVoiceProcessing) {
+    return;
+  }
+
+  if (self.audioEngine.isRunning) {
+    [self.audioEngine stop];
+  }
+
+  NSError *vpError = nil;
+  if (![systemInputNode setVoiceProcessingEnabled:wantsVoiceProcessing error:&vpError]) {
+    NSLog(@"[AudioEngine] setVoiceProcessingEnabled:%d failed: %@", wantsVoiceProcessing, vpError);
+  }
+}
+
 - (void)materializeTrackedNodesIfNeeded
 {
   NSArray<NSString *> *sourceNodeIds =