u can use "festival" in Linux
Description: general multi-lingual speech synthesis system
Festival offers a full text to speech system with various APIs, as well an
environment for development and research of speech synthesis techniques. It
includes a Scheme-based command interpreter.
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Besides research into speech synthesis, festival is useful as a stand-alone
speech synthesis program. It is capable of producing clearly understandable
speech from text.
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Homepage: <*www.festvox.org/packed/festival/>