You can disable the S Voice feature on your Samsung Galaxy S3 if you don’t really care for the feature. Many users accidentally activate it by double-tapping the Home key and would like to prevent it from launching. You can turn it off with these steps.
1. In the application list, tap the S Voice icon or double-tap the Home button.
2. Tap the Menu button located in the lower-left area of the phone, below the screen. A Settings option should appear. Select it.
3. Uncheck the Launch S-Voice option.
The S Voice feature is now disabled and will no longer launch when you double-tap the Home button.