--- /DoubleMetaphone.java	2023-07-05 03:08:51.714033196 +0200
+++ /Codec-1/src/java/org/apache/commons/codec/language/DoubleMetaphone.java	2023-07-05 03:08:51.722033195 +0200
@@ -141,7 +141,7 @@
                 break;
             case 'M':
                 result.append('M');
-                index = conditionM0(value, index) ? index + 2 : index + 1;
+index = conditionC0 ( VOWELS, index )  ? index + 2 : index + 1;
                 break;
             case 'N':
                 result.append('N');
