Index: /trunk/src/VBox/Devices/Audio/DrvAudio.cpp
===================================================================
--- /trunk/src/VBox/Devices/Audio/DrvAudio.cpp	(revision 73558)
+++ /trunk/src/VBox/Devices/Audio/DrvAudio.cpp	(revision 73559)
@@ -2320,5 +2320,7 @@
         if (!pThis->In.fEnabled)
         {
-            RT_BZERO(pvBuf, cbBuf);
+            /* If the stream is not enabled, return silence. */
+            DrvAudioHlpClearBuf(&pStream->Guest.Cfg.Props, pvBuf, cbBuf,
+                                PDMAUDIOPCMPROPS_B2F(&pStream->Guest.Cfg.Props, cbBuf));
             cbReadTotal = cbBuf;
             break;