Since updating to ios10, voice control intermittently launches itself,also between Sounds and Touch id/password under settings the menu for Siri has disappeared.
Voice Control is launching on its own,also since updating to ios10 there is no menu to turn off Siri between Sounds and Touch id and password
sirivoice
Related Solutions
Voice Control is still available on the iPhone 4S, unless you have enabled Siri in the iPhone preferences (listed under the General menu).
If Siri is disabled, holding the Home button will still launch the "classic" voice control, which does work offline, and also supports a whole lot more languages than Siri currently does.
As of iOS 10.2.1 (maybe as early as 10.2), it is possible to disable Voice Control.
Settings > General > Accessibility > Home Button
There is a setting PRESS AND HOLD TO SPEAK. Set this to Off. The descriptive text is "There will be no response when you press and hold the Home button."
I would like to thank Bob Briscoe for providing this answer, which he received from Apple Support. Since the question is protected, he cannot post an answer himself, so I am posting on his behalf.
Best Answer
Siri is disabled under Restrictions. To re-enable Siri, go into Settings > General > Restrictions, enter your Restrictions password, and enable Siri and Dictation.