$OpenBSD$

OpenBSD (others?) has soundcard.h in /usr/include

--- configure.orig	Fri Jun 19 00:26:30 2015
+++ configure	Fri Jun 19 00:26:44 2015
@@ -13415,7 +13415,7 @@ echo "$as_me: error: plugin directory \"$srcdir/dll/$p
 
 
 
-for ac_header in machine/soundcard.h linux/soundcard.h sys/soundcard.h
+for ac_header in machine/soundcard.h linux/soundcard.h sys/soundcard.h soundcard.h
 do
 as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
 if eval "test \"\${$as_ac_Header+set}\" = set"; then
@@ -14898,7 +14898,7 @@ echo "$as_me: error: plugin directory \"$srcdir/dll/$p
 
 
 
-for ac_header in machine/soundcard.h linux/soundcard.h sys/soundcard.h
+for ac_header in machine/soundcard.h linux/soundcard.h sys/soundcard.h soundcard.h
 do
 as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
 if eval "test \"\${$as_ac_Header+set}\" = set"; then
