p.s. There's also handsfree voice dialers.
Handsfree Freedom Voice Dialers and voice activated telephones. They're quite pricey though.
http://www.dynamic-living.com/telephones.htm

This emergency dialer unit will contact neighbors, friends, relatives or emergency personnel with the touch of a button.
http://www.dynamic-living.com/telemergency.htm

This is a bit like the one I've seen in aged care facilities...
Two Pendant Paging System
http://www.dynamic-living.com/two-pendant-pager.htm

Safety and Emergency Help products
http://www.dynamic-living.com/safety.htm

Channel Wireless Intercom -The wireless intercom has up to a 1000 foot range.
http://www.dynamic-living.com/wireless_intercom.htm