DESIGN AND IMPLEMENTATION OF TEXT – TO- SPEECH/AUDIO SYSTEM. A RESEARCH PROJECT MATERIAL ON COMPUTER SCIENCE EDUCATION
Design and Implementation of a Text-to-speech/audio system is the generation of synthesized speech from text. The purpose of this paper is to make synthesized speech as intelligible, natural and pleasant to listen, as human speech. Speech is the primary means of communication between people.
During synthesis very small segments of recorded human speech are concatenated together to produce the synthesized speech.
The quality of a speech synthesizer is judged by its similarity to the human voice and by its ability to be understood. A text-to-speech synthesizer allows people with visual impairments and reading disabilities to listen to written works on a home computer.
Language is the ability to express one’s thoughts by means of a set of signs (text), gestures, and sounds. It is a distinctive feature of human beings, who are the only creatures to use such a system. Speech is the oldest means of communication between people and it is also the most widely used. ‘Speech synthesis’ also called ‘Text to 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.
A text-to-speech (TTS) system simply converts text to speech. Many computer operating systems have included speech synthesizers since the early 1990s.
Recent progress in speech synthesis has produced synthesizers with very high intelligibility but the sound quality and naturalness still remain a major problem. However, the quality of present products has reached an adequate level for several applications, such as multimedia and telecommunications.
The following thesis presents a brief overview of the main text-to-speech synthesis problems, and the initial work done in building a TTS in English.
At first sight, this task does not look too hard to perform. After all we all have a deep knowledge of reading rules of our mother tongue. They were transmitted to us, in a simplified form, at primary school, and we improved them year after year. But in the context of TTS synthesis, it is impossible to record and store all the words of the language. Some other method has to be implemented for this purpose. The quality of a speech synthesizer is judged by its similarity to the human voice and by its ability to be understood. A text-to-speech synthesizer allows people with visual impairments and reading disabilities to listen to written works on a home computer. Many computer operating systems have included speech synthesizers since the early 1990s.
Astro- physician Stephen Hawkins, who is completely paralyzed, gives all his lectures using a TTS system.
Text-to-speech synthesis -TTS – is the automatic conversion of a text into speech that resembles, as closely as possible, a native speaker of the language reading that text. Text-to-speech/ Audio system is the technology which lets computer speak to you. The TTS system gets the text as the input and then a computer algorithm which called TTS engine analyses the text, pre-processes the text and synthesizes the speech with some mathematical models. The TTS engine usually generates sound data in an audio format as the output.
The text-to-speech (TTS) synthesis procedure consists of two main phases. The first is text analysis, where the input text is transcribed into a phonetic or some other linguistic representation, and the second one is the generation of speech waveforms, where the output is produced from this phonetic and prosodic information. These two phases are usually called high and low-level synthesis. The input text might be for example data from a word processor, standard ASCII from e-mail, a mobile text-message, or scanned text from a newspaper. The character string is then pre-processed and analyzed into phonetic representation which is usually a string of phonemes with some additional information for correct intonation, duration, and stress. Speech sound is finally generated with the low-level synthesizer by the information from high-level one. The artificial production of speech-like sounds has a long history, with documented mechanical attempts dating to the eighteenth century.