This paper describes an experiment to show how the comprehensibility of speech over the telephone may be related to the age of the listener. Although it is believed by many that as we age, our ability to understand natural or synthesized spoken language, over a telephone degrades, most evidence is anecdotal at best. We therefore devised and carried out the following simple experiment to serve as a point of departure for examining and proving the degradation. The term, "understanding", is defined here as hearing, processing, and correctly reacting to spoken computer output since one or more of these three activities may be degraded for any given elderly user.
Our motivation for confirming this hypothesis is to fuel research oriented toward improving the usefulness of telephone-based information presentation systems for elderly users. The elderly do not for the most part have computers to access the internet and the information that they need for everyday life. They do, however, have telephones and, if dialogues with the elderly users are conducted correctly, the phone can replace the computer as a means of access to information such as bus schedules and medical appointments. A dialogue system could also be used in such applications as the automated home nursing robot for the elderly .
Using this newly-gained understanding of how speech comprehension degrades as users age, we can accordingly improve speech synthesis to be clearer to the user and oral dialogue quality to be efficient and effective.