diff --git a/Message/Notification/App/AppNotification.js b/Message/Notification/App/AppNotification.js
index e69de29..d520214 100644
--- a/Message/Notification/App/AppNotification.js
+++ b/Message/Notification/App/AppNotification.js
@@ -0,0 +1,34 @@
+/**
+ * App notification.
+ *
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @since      1.0.0
+ */
+(function (jsOMS)
+{
+    "use strict";
+
+    /** @namespace jsOMS.Message.Notification.App */
+    jsOMS.Autoloader.defineNamespace('jsOMS.Message.Notification.App');
+
+    jsOMS.Message.Notification.App.AppNotification = function()
+    {
+        this.status = 0;
+    };
+
+    jsOMS.Message.Notification.App.AppNotification.prototype.setStatus = function(status)
+    {
+        this.status = status;
+    }
+
+    jsOMS.Message.Notification.App.AppNotification.prototype.requestPermission = function()
+    {
+        const self = this;
+    };
+
+    jsOMS.Message.Notification.App.AppNotification.prototype.send = function(msg)
+    {
+    };
+}(window.jsOMS = window.jsOMS || {}));
\ No newline at end of file
diff --git a/UI/Input/Voice/ReadManager.js b/UI/Input/Voice/ReadManager.js
index 7d844fb..74de2c7 100644
--- a/UI/Input/Voice/ReadManager.js
+++ b/UI/Input/Voice/ReadManager.js
@@ -14,9 +14,9 @@
     jsOMS.Autoloader.defineNamespace('jsOMS.UI.Input.Voice');
 
     // todo: remove once obsolete
-    var SpeechRecognition = SpeechRecognition || webkitSpeechRecognition
-    var SpeechGrammarList = SpeechGrammarList || webkitSpeechGrammarList
-    var SpeechRecognitionEvent = SpeechRecognitionEvent || webkitSpeechRecognitionEvent
+    var SpeechRecognition = typeof SpeechRecognition !== 'undefined' ? SpeechRecognition : typeof webkitSpeechRecognition !== 'undefined' ? webkitSpeechRecognition : null;
+    var SpeechGrammarList = typeof SpeechGrammarList !== 'undefined' ? SpeechGrammarList : typeof webkitSpeechGrammarList !== 'undefined' ? webkitSpeechGrammarList : null;
+    var SpeechRecognitionEvent = typeof SpeechRecognitionEvent !== 'undefined' ? SpeechRecognitionEvent : typeof webkitSpeechRecognitionEvent !== 'undefined' ? webkitSpeechRecognitionEvent : null;
 
     /**
      * @constructor
@@ -28,9 +28,13 @@
         this.pitch = 1;
         this.rate = 1;
         this.lang = typeof lang === 'undefined' ? 'en-US' : lang;    
-        
-        this.voices = window.speechSynthesis.getVoices();
-        this.voice = this.voices[0];
+        this.voices = [];
+        this.voice = null;
+
+        if(SpeechRecognition !== null) {
+            this.voices = window.speechSynthesis.getVoices();
+            this.voice = this.voices[0];
+        }
     };
 
     /**
diff --git a/UI/Input/Voice/VoiceManager.js b/UI/Input/Voice/VoiceManager.js
index 851ce5b..2799dce 100644
--- a/UI/Input/Voice/VoiceManager.js
+++ b/UI/Input/Voice/VoiceManager.js
@@ -14,9 +14,9 @@
     jsOMS.Autoloader.defineNamespace('jsOMS.UI.Input.Voice');
 
     // todo: remove once obsolete
-    var SpeechRecognition = SpeechRecognition || webkitSpeechRecognition
-    var SpeechGrammarList = SpeechGrammarList || webkitSpeechGrammarList
-    var SpeechRecognitionEvent = SpeechRecognitionEvent || webkitSpeechRecognitionEvent
+    var SpeechRecognition = typeof SpeechRecognition !== 'undefined' ? SpeechRecognition : typeof webkitSpeechRecognition !== 'undefined' ? webkitSpeechRecognition : null;
+    var SpeechGrammarList = typeof SpeechGrammarList !== 'undefined' ? SpeechGrammarList : typeof webkitSpeechGrammarList !== 'undefined' ? webkitSpeechGrammarList : null;
+    var SpeechRecognitionEvent = typeof SpeechRecognitionEvent !== 'undefined' ? SpeechRecognitionEvent : typeof webkitSpeechRecognitionEvent !== 'undefined' ? webkitSpeechRecognitionEvent : null;
 
     /**
      * @constructor
@@ -26,10 +26,15 @@
     jsOMS.UI.Input.Voice.VoiceManager = function (app, commands, lang)
     {
         this.app = app;
-        this.recognition = new SpeechRecognition();
-        this.speechRecognitionList = new SpeechGrammarList();
         this.commands = typeof commands === 'undefined' ? {} : commands;
-        this.lang = typeof lang === 'undefined' ? 'en-US' : lang;      
+        this.lang = typeof lang === 'undefined' ? 'en-US' : lang;
+        this.recognition = null;
+        this.speechRecognitionList = null;
+
+        if(SpeechRecognition !== null) {
+            this.recognition = new SpeechRecognition();
+            this.speechRecognitionList = new SpeechGrammarList();
+        }
     };
 
     /**
@@ -41,6 +46,10 @@
      */
     jsOMS.UI.Input.Voice.VoiceManager.prototype.setup = function()
     {
+        if(SpeechRecognition === null) {
+            return;
+        }
+
         const self = this;
 
         this.recognition.lang = this.lang;
@@ -127,6 +136,10 @@
      */
     jsOMS.UI.Input.Voice.VoiceManager.prototype.start = function()
     {
+        if(SpeechRecognition === null) {
+            return;
+        }
+
         this.recognition.start();
     };
 
@@ -139,6 +152,10 @@
      */
     jsOMS.UI.Input.Voice.VoiceManager.prototype.stop = function()
     {
+        if(SpeechRecognition === null) {
+            return;
+        }
+        
         this.recognition.stop();
     };
 }(window.jsOMS = window.jsOMS || {}));
\ No newline at end of file