added "updateAudioBar" function signature in header file

interface/resources/qml/hifi/tablet/Tablet.qml

@@ -10,7 +10,7 @@ Item {
     width: parent.width
     height: parent.height
 
-    // called by C++ code to keep mic level display bar UI updated
+    // called by C++ code to keep audio bar updated
     function setMicLevel(newMicLevel) {
         tablet.micLevel = newMicLevel;
     }

libraries/script-engine/src/TabletScriptingInterface.h

@@ -84,6 +84,13 @@ public:
      */
     Q_INVOKABLE void removeButton(QObject* tabletButtonProxy);
 
+    /**jsdoc
+     * @function TabletProxy#updateAudioBar
+     * Updates the audio bar in tablet to reflect latest mic level
+     * @param micLevel {double} mic level value between 0 and 1
+     */
+    Q_INVOKABLE void updateAudioBar(const double micLevel);
+    
     QString getName() const { return _name; }
 protected: