How to disable default sound effects for all my application or activity

Create a theme file “res/values/styles.xml”

<?xml version="1.0" encoding="utf-8"?>
<resources>

<style name="AppBaseTheme" parent="android:Theme.Black.NoTitleBar">
    <!--
        Theme customizations available in newer API levels can go in
        res/values-vXX/styles.xml, while customizations related to
        backward-compatibility can go here.
    -->
</style>

<!-- Application theme. -->
<style name="AppTheme" parent="AppBaseTheme">
    <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    <item name="android:soundEffectsEnabled">false</item>
</style>

</resources>

And then reference to it in your “AndroidManifest.xml”

<application
    ...
    android:theme="@style/AppTheme" >