diff --git a/app/build.gradle b/app/build.gradle
index 47f1cbb..eccc802 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -43,5 +43,5 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     testCompile 'junit:junit:4.12'
-    compile 'com.github.axet:android-audio-library:0.0.50' // compile project(':android-audio-library')
+    compile 'com.github.axet:android-audio-library:0.0.51' // compile project(':android-audio-library')
 }
diff --git a/app/src/main/java/com/github/axet/audiorecorder/app/Storage.java b/app/src/main/java/com/github/axet/audiorecorder/app/Storage.java
index b376e3e..f9ece44 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/app/Storage.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/app/Storage.java
@@ -10,9 +10,6 @@ import java.util.Date;
 
 public class Storage extends com.github.axet.audiolibrary.app.Storage {
 
-    SimpleDateFormat SIMPLE = new SimpleDateFormat("yyyy-MM-dd HH.mm.ss");
-    SimpleDateFormat ISO8601 = new SimpleDateFormat("yyyyMMdd'T'HHmmss");
-
     public Storage(Context context) {
         super(context);
     }