speech synthesis

creation through the use of a computer of sound output which resembles human speech

Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware. A text-to-speech (TTS) system converts normal language text into speech; other systems render symbolic linguistic representations like phonetic transcriptions into speech.
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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 or say a phrase.