diff --git a/phsource/ph_vietnam b/phsource/ph_vietnam
index 8578639c..6c8a6308 100644
--- a/phsource/ph_vietnam
+++ b/phsource/ph_vietnam
@@ -819,10 +819,11 @@ phoneme d_
   vcd alv stp
     //	lengthmod 5
 	ipa ɗ
-	length 50
- Vowelin f1=1  f2=1700 -300 300  f3=-100 80 len=15
-  Vowelout f1=2 f2=1700 -300 300  f3=-100 80 brk len=30
-WAV(vietnam/dd_2)
+	length 70
+	Vowelin f1=1  f2=1500 -300 300  f3=-100 80 len=15
+	Vowelout f1=2 f2=1700 -300 300  f3=-100 80 brk len=30
+	WAV(vietnam/dda_2, 200)
+	
  endphoneme
  
  phoneme c
diff --git a/phsource/vietnam/dda.wav b/phsource/vietnam/dda.wav
new file mode 100644
index 00000000..218f3bf2
Binary files /dev/null and b/phsource/vietnam/dda.wav differ
diff --git a/phsource/vietnam/dda_2.wav b/phsource/vietnam/dda_2.wav
new file mode 100644
index 00000000..9532aa8b
Binary files /dev/null and b/phsource/vietnam/dda_2.wav differ