There are services that allow you to carry an alarm button which will make an automatic phone call to a healthcare facility or security agency. Some medical equipment can have similar features, in which a phone call is made if the machine experiences a shutdown that could be life-threatening. Dedicated phone lines might be needed in these cases. Many telephone companies have disability programs to provide special equipment. For example, Pacific Bell gives people speaker phones or headsets free of charge once you and your physician fill out the application.
Telephones are available with large, lighted buttons which are easy to press.
Hands-free telephone access is possible. A remote phone goes where you go, which is especially helpful in the bathroom. These products have improved a great deal in recent years. The sound quality is good, multiple channels are available in case you get static, and 2.4 GHz phones can have a range of 1,000 feet or more. Now that I have a remote phone, I never miss calls.