diff --git a/sdk/objc/components/audio/RTCAudioSession+Private.h b/sdk/objc/components/audio/RTCAudioSession+Private.h
index 8ee4fdd..4f5107f 100644
--- a/sdk/objc/components/audio/RTCAudioSession+Private.h
+++ b/sdk/objc/components/audio/RTCAudioSession+Private.h
@@ -73,6 +73,12 @@
 /** Returns a configuration error with the given description. */
 - (NSError *)configurationErrorWithDescription:(NSString *)description;
 
+/** Notifies the reciever that a playout glitch was detected. */
+- (void)notifyDidDetectPlayoutGlitch:(int64_t)totalNumberOfGlitches;
+
+/** Notifies the reciever that there was an error when starting an audio unit. */
+- (void)notifyAudioUnitStartFailedWithError:(OSStatus)error;
+
 // Properties and methods for tests.
 - (void)notifyDidBeginInterruption;
 - (void)notifyDidEndInterruptionWithShouldResumeSession:(BOOL)shouldResumeSession;
@@ -83,7 +89,6 @@
 - (void)notifyDidChangeCanPlayOrRecord:(BOOL)canPlayOrRecord;
 - (void)notifyDidStartPlayOrRecord;
 - (void)notifyDidStopPlayOrRecord;
-- (void)notifyDidDetectPlayoutGlitch:(int64_t)totalNumberOfGlitches;
 
 @end
 
diff --git a/sdk/objc/components/audio/RTCAudioSession.h b/sdk/objc/components/audio/RTCAudioSession.h
index 5881155..3b83b27 100644
--- a/sdk/objc/components/audio/RTCAudioSession.h
+++ b/sdk/objc/components/audio/RTCAudioSession.h
@@ -99,6 +99,9 @@
     failedToSetActive:(BOOL)active
                 error:(NSError *)error;
 
+- (void)audioSession:(RTC_OBJC_TYPE(RTCAudioSession) *)audioSession
+    audioUnitStartFailedWithError:(NSError *)error;
+
 @end
 
 /** This is a protocol used to inform RTCAudioSession when the audio session
diff --git a/sdk/objc/components/audio/RTCAudioSession.mm b/sdk/objc/components/audio/RTCAudioSession.mm
index 057f62c..5031e15 100644
--- a/sdk/objc/components/audio/RTCAudioSession.mm
+++ b/sdk/objc/components/audio/RTCAudioSession.mm
@@ -794,6 +794,18 @@
   }
 }
 
+- (void)notifyAudioUnitStartFailedWithError:(OSStatus)error {
+  for (auto delegate : self.delegates) {
+    SEL sel = @selector(audioSession:audioUnitStartFailedWithError:);
+    if ([delegate respondsToSelector:sel]) {
+      [delegate audioSession:self
+          audioUnitStartFailedWithError:[NSError errorWithDomain:kRTCAudioSessionErrorDomain
+                                                            code:error
+                                                        userInfo:nil]];
+    }
+  }
+}
+
 - (void)notifyDidBeginInterruption {
   for (auto delegate : self.delegates) {
     SEL sel = @selector(audioSessionDidBeginInterruption:);
diff --git a/sdk/objc/native/src/audio/audio_device_ios.mm b/sdk/objc/native/src/audio/audio_device_ios.mm
index e3020ec..3ec7d0b 100644
--- a/sdk/objc/native/src/audio/audio_device_ios.mm
+++ b/sdk/objc/native/src/audio/audio_device_ios.mm
@@ -235,8 +235,11 @@
     fine_audio_buffer_->ResetPlayout();
   }
   if (!recording_ && audio_unit_->GetState() == VoiceProcessingAudioUnit::kInitialized) {
-    if (!audio_unit_->Start()) {
-      RTCLogError(@"StartPlayout failed to start audio unit.");
+    OSStatus result = audio_unit_->Start();
+    if (result != noErr) {
+      RTC_OBJC_TYPE(RTCAudioSession)* session = [RTC_OBJC_TYPE(RTCAudioSession) sharedInstance];
+      [session notifyAudioUnitStartFailedWithError:result];
+      RTCLogError(@"StartPlayout failed to start audio unit, reason %d", result);
       return -1;
     }
     RTC_LOG(LS_INFO) << "Voice-Processing I/O audio unit is now started";
@@ -288,8 +291,11 @@
     fine_audio_buffer_->ResetRecord();
   }
   if (!playing_ && audio_unit_->GetState() == VoiceProcessingAudioUnit::kInitialized) {
-    if (!audio_unit_->Start()) {
-      RTCLogError(@"StartRecording failed to start audio unit.");
+    OSStatus result = audio_unit_->Start();
+    if (result != noErr) {
+      RTC_OBJC_TYPE(RTCAudioSession)* session = [RTC_OBJC_TYPE(RTCAudioSession) sharedInstance];
+      [session notifyAudioUnitStartFailedWithError:result];
+      RTCLogError(@"StartRecording failed to start audio unit, reason %d", result);
       return -1;
     }
     RTC_LOG(LS_INFO) << "Voice-Processing I/O audio unit is now started";
@@ -620,9 +626,16 @@
   }
 
   // Restart the audio unit if it was already running.
-  if (restart_audio_unit && !audio_unit_->Start()) {
-    RTCLogError(@"Failed to start audio unit with sample rate: %f", session_sample_rate);
-    return;
+  if (restart_audio_unit) {
+    OSStatus result = audio_unit_->Start();
+    if (result != noErr) {
+      RTC_OBJC_TYPE(RTCAudioSession)* session = [RTC_OBJC_TYPE(RTCAudioSession) sharedInstance];
+      [session notifyAudioUnitStartFailedWithError:result];
+      RTCLogError(@"Failed to start audio unit with sample rate: %f, reason %d",
+                  session_sample_rate,
+                  result);
+      return;
+    }
   }
   RTCLog(@"Successfully handled sample rate change.");
 }
@@ -801,8 +814,10 @@
     // Log session settings before trying to start audio streaming.
     RTC_OBJC_TYPE(RTCAudioSession)* session = [RTC_OBJC_TYPE(RTCAudioSession) sharedInstance];
     RTCLog(@"%@", session);
-    if (!audio_unit_->Start()) {
-      RTCLogError(@"Failed to start audio unit.");
+    OSStatus result = audio_unit_->Start();
+    if (result != noErr) {
+      [session notifyAudioUnitStartFailedWithError:result];
+      RTCLogError(@"Failed to start audio unit, reason %d", result);
       return;
     }
   }
diff --git a/sdk/objc/native/src/audio/voice_processing_audio_unit.h b/sdk/objc/native/src/audio/voice_processing_audio_unit.h
index 72e29c0..ed9dd98 100644
--- a/sdk/objc/native/src/audio/voice_processing_audio_unit.h
+++ b/sdk/objc/native/src/audio/voice_processing_audio_unit.h
@@ -78,7 +78,7 @@
   bool Initialize(Float64 sample_rate);
 
   // Starts the underlying audio unit.
-  bool Start();
+  OSStatus Start();
 
   // Stops the underlying audio unit.
   bool Stop();
diff --git a/sdk/objc/native/src/audio/voice_processing_audio_unit.mm b/sdk/objc/native/src/audio/voice_processing_audio_unit.mm
index 2325b2e..661022f 100644
--- a/sdk/objc/native/src/audio/voice_processing_audio_unit.mm
+++ b/sdk/objc/native/src/audio/voice_processing_audio_unit.mm
@@ -332,19 +332,19 @@
   return true;
 }
 
-bool VoiceProcessingAudioUnit::Start() {
+OSStatus VoiceProcessingAudioUnit::Start() {
   RTC_DCHECK_GE(state_, kUninitialized);
   RTCLog(@"Starting audio unit.");
 
   OSStatus result = AudioOutputUnitStart(vpio_unit_);
   if (result != noErr) {
     RTCLogError(@"Failed to start audio unit. Error=%ld", (long)result);
-    return false;
+    return result;
   } else {
     RTCLog(@"Started audio unit");
   }
   state_ = kStarted;
-  return true;
+  return noErr;
 }
 
 bool VoiceProcessingAudioUnit::Stop() {