diff --git a/media/audio/win/audio_session_creation_observer_win.cc b/media/audio/win/audio_session_creation_observer_win.cc
--- a/media/audio/win/audio_session_creation_observer_win.cc
+++ b/media/audio/win/audio_session_creation_observer_win.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

+#include <windows.h>
+
 #include "media/audio/win/audio_session_creation_observer_win.h"

 #include <unknwn.h>
@@ -37,6 +39,10 @@ HRESULT AudioSessionCreationObserverWin::QueryInterface(REFIID iid,

 HRESULT AudioSessionCreationObserverWin::OnSessionCreated(
     IAudioSessionControl* session) {
+  // POC instrumentation: widen the race window so the UI thread can free
+  // |this| between the MM thread loading the vtable and dereferencing
+  // session_created_cb_. Remove for real-world timing.
+  ::Sleep(50);
   session_created_cb_.Run();
   return S_OK;
 }
diff --git a/media/audio/win/audio_ducker_win.cc b/media/audio/win/audio_ducker_win.cc
--- a/media/audio/win/audio_ducker_win.cc
+++ b/media/audio/win/audio_ducker_win.cc
@@ -106,6 +106,9 @@ AudioDuckerWin::AudioDuckerWin(ShouldDuckProcessCallback callback)

 AudioDuckerWin::~AudioDuckerWin() {
   StopDuckingOtherWindowsApplications();
+  // POC instrumentation: force the std::unique_ptr free now (member dtor would
+  // do this anyway one line later) so ASan poisons the slot before the sleeping
+  // MM-thread callback resumes.
+  session_creation_observer_.reset();
 }

 void AudioDuckerWin::StartDuckingOtherWindowsApplications() {