diff --git a/lib/filter/sim/in2wav.m b/lib/filter/sim/in2wav.m
new file mode 100644
index 0000000..ad5221e
--- /dev/null
+++ b/lib/filter/sim/in2wav.m
@@ -0,0 +1,8 @@
+function in2wav(name)
+
+fid = fopen(name, 'r');
+x = fread(fid, 'int');
+fclose(fid);
+
+wavwrite(x*(2^-15), 44100, 'wav_out.wav');
+
diff --git a/lib/filter/sim/wav2in.m b/lib/filter/sim/wav2in.m
new file mode 100644
index 0000000..de385b4
--- /dev/null
+++ b/lib/filter/sim/wav2in.m
@@ -0,0 +1,8 @@
+function wav2in(name)
+
+x = wavread(name)*(2^15);
+
+fid = fopen('wav_in.dat', 'w');
+fwrite(fid, fix(x), 'int');
+fclose(fid);
+