Yes! The Tecla Shield DOS enables totally hands-free and independent access to Siri on your iPhone, iPad and iPod Touch using as little as a single switch. Users of the newer Switch Control feature available from iOS7 can access Siri from the Switch Control menu, while all others can access Siri by pressing and holding on the switch they use to select items.
Users of the older Tecla Shield UNO cannot use their switches or other alternative input methods to access Siri, however, we have had reports from users who are able to successfully launch Siri with the Tecla Shield UNO using SiriBoard (http://www.ijailbreak.com/cydia/siriboard-cydia-tweak/) on jailbroken iOS devices. Though we do not encourage jailbreaking, we do believe users have the right to know the solution exists.