diff -ruN src/h323ep.cxx.orig src/h323ep.cxx
--- src/h323ep.cxx.orig     2006-06-09 02:30:12.000000000 -0400
+++ src/h323ep.cxx 2007-12-31 13:11:13.000000000 -0500
@@ -793,6 +793,7 @@
 #include <ptclib/url.h>
 #include <ptclib/pils.h>
 #include <ptclib/enum.h>
+#include <ptlib/sound.h>

 #if defined(H323_RTP_AGGREGATE) || defined(H323_SIGNAL_AGGREGATE)
 #include <ptclib/sockagg.h>