Samsung’s S Voice feature has improved considerably since its initial release, but if you’re still not a regular user of the feature it’s worth disabling it to get improved performance from your handset.
Going by the default settings of TouchWiz, S Voice is activated when you double tap the home key. This means that when you press the home key once, there is a short pause while the handset waits to see if a second tap is registered to activate S Voice. If you’re not using S Voice all that much, you may wish to disable the double tap feature to remove the lag.
To do this, load S Voice and go to menu > settings > open via the home key.
If you don’t want to disable S Voice but still want to speed up the home button, you could use gesture controls to launch the app instead. These are included within some launchers or can be configured with other apps, such as Trigger.
S Voice runs on Samsung’s Android handsets that have been updated to Jelly Bean, so you should be able to make the tweak on the Samsung Galaxy S2/S3/S4 and both the Galaxy Note and Galaxy Note 2.