With the decreasing cost of fax machines, this technique is looking increasingly attractive as a means for providing a remote reading service. Speech technology Recent developments in speech technology have led to significant improvements in quality and accuracy, and a reduction in prices. This is important for people with disabilities since speech technology can be used for interpersonal communication, access to information and control of the environment. Although the intelligibility of the available speech synthesis systems is quite high for a number of languages, there is evidence that significantly better quality should be achievable. Other important research areas are modelling of emotions and speech synthesis from the meaning of the text.
Continuous speech adds more difficulties.
Speaker and environmental differences are very important. There is insufficient knowledge about the human language understanding process. These systems are for the general public and therefore have to cope with significant variances between individual speakers. Current systems are limited to vocabularies of a few hundred words, but laboratory prototypes exist with vocabularies of a few thousand words. If the system is trained for an individual speaker then accuracy dramatically improves, large vocabularies can be used and the cost comes down to a modest level.