diff --git a/src/libespeak-ng/wavegen.c b/src/libespeak-ng/wavegen.c
index cc9d9dd4..88d787b7 100644
--- a/src/libespeak-ng/wavegen.c
+++ b/src/libespeak-ng/wavegen.c
@@ -918,6 +918,10 @@ static int PlaySilence(int length, bool resume)
 	if (length == 0)
 		return 0;
 
+#if HAVE_SONIC_H
+	length = (int)(length * sonicSpeed);
+#endif
+
 	if (resume == false)
 		n_samples = length;