The Free On-line Dictionary of Computing (30 December 2018):

speech synthesis

   The generation of an sound waveform of human speech from a
   textual or phonetic description.  See also speech
   recognition.

   There are demonstrations which say a number
   (http://cs.yale.edu/cgi-bin/saynumber.au) or say a
   phrase (http://wwwtios.cs.utwente.nl/say/form/).