<animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:oneshot="false">

    <item android:drawable="@drawable/voice_msg_playing_1" android:duration="400"/>
    <item android:drawable="@drawable/voice_msg_playing_2" android:duration="400"/>
    <item android:drawable="@drawable/voice_msg_playing_3" android:duration="400"/>

</animation-list>