A good SUI has a natural, human-like quality. There is no need to associate
a function with a number (in contrast to touchtone user interfaces) when speech
labels provide good functional descriptions. System prompts become much shorter
and more natural, and it is possible to add options in the future without
any need to change existing speech labels, even if the order of functions
changes. Finally, there is no need for a user to move the phone away from
his or her ear to find the button to press.
A Harris survey conducted in 2003 supports the claim of the effectiveness
of speech applications with the following results:
- Speech is widely used and accepted (only 7% of respondents in the survey
would avoid future use of speech systems).
- Consumers reported high satisfaction with speech experiences (61% highly
satisfied with most recent speech interaction).
- Consumers feel that speech provides many advantages over other e-Service
methods (90% of respondents preferred speech to touchtone systems).