diff --git a/app/src/main/cpp/sox/mat4.c b/app/src/main/cpp/sox/mat4.c
deleted file mode 100644
index 7af2b93..0000000
--- a/app/src/main/cpp/sox/mat4.c
+++ /dev/null
@@ -1,33 +0,0 @@
-/* libSoX file format: MatLab4   Copyright (c) 2008 robs@users.sourceforge.net
- *
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or (at
- * your option) any later version.
- *
- * This library is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
- * General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- */
-
-#include "sox_i.h"
-
-LSX_FORMAT_HANDLER(mat4)
-{
-  static char const * const names[] = {"mat4", "mat", NULL};
-  static unsigned const write_encodings[] = {
-    SOX_ENCODING_SIGN2, 16, 32, 0,
-    SOX_ENCODING_FLOAT, 32, 64, 0,
-    0};
-  static sox_format_handler_t handler;
-  handler = *lsx_sndfile_format_fn();
-  handler.description = "Gnu Octave 2.0 format";
-  handler.names = names;
-  handler.write_formats = write_encodings;
-  return &handler;
-}
diff --git a/app/src/main/cpp/sox/mat5.c b/app/src/main/cpp/sox/mat5.c
deleted file mode 100644
index e29a18d..0000000
--- a/app/src/main/cpp/sox/mat5.c
+++ /dev/null
@@ -1,33 +0,0 @@
-/* libSoX file format: MatLab5   Copyright (c) 2008 robs@users.sourceforge.net
- *
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or (at
- * your option) any later version.
- *
- * This library is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
- * General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- */
-
-#include "sox_i.h"
-
-LSX_FORMAT_HANDLER(mat5)
-{
-  static char const * const names[] = {"mat5", NULL};
-  static unsigned const write_encodings[] = {
-    SOX_ENCODING_SIGN2, 16, 32, 0,
-    SOX_ENCODING_FLOAT, 32, 64, 0,
-    0};
-  static sox_format_handler_t handler;
-  handler = *lsx_sndfile_format_fn();
-  handler.description = "Gnu Octave 2.1 format";
-  handler.names = names;
-  handler.write_formats = write_encodings;
-  return &handler;
-}