DESIGN AND IMPLEMENTATION OF TEXT-TO-SPEECH / AUDIO SYSTEM

1.1 Introduction

Text-to-Speech software can "read" text from a document, Web page or e-Book, generating synthesized speech through a computer's speakers. This can save time by allowing the user to listen to reports or background materials while performing other tasks. Text-to-Speech makes a critical difference to those with disabilities such as poor vision or visual dyslexia. People with speech loss can utilize specialized Text-to-Speech programs to turn typed words into vocalization.

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.

1.2 Background of Study

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 synthesizerand can be implemented in software. A text-to-speech (Text-to-Speech)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 Text-to-Speech 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 Text-to-Speech 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 Text-to-Speech system.

Text-to-Speech - 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 Text-to-Speech system gets the text as the input and then a computer algorithm which called Text-to-Speech engine analyses the text, pre-processes the text and synthesizes the speech with some mathematical models. The Text-to-Speech engine usually generates sound data in an audio format as the output. The text-to-speech (Text-to-Speech) 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 [O' Shaughnessy 2004].

Speech synthesis can be described as 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 (Text-to-Speech) system converts normal language text into speech. Synthesized speech can be created by concatenating pieces of recorded speech that are stored in a database. Systems differ in the size of the stored speech units; a system that stores phones or diaphones provides the largest output range, but may lack clarity. For specific usage domains, the storage of entire words or sentences allows for high-quality output.

1.3 Statement of the Problem

The importance of texts cannot be overemphasized. Hardly can anyone pass a message without including one form of text or the other. This is a problem for the visually impaired. They find it hard to read through the texts especially when the font-size is small. This has led to the development of a Text-to-Speech conversion system. For those with learning disabilities, some in literary levels, they often get frustrated trying to browse the internet because so much of it is in text form.

Also in some already developed speech synthesizers, the problem area in speech synthesis is very wide. There are several problems in text pre-processing, such as numerals, abbreviations, and acronyms. This system will help solve the problems by using well written synthesis algorithm for the conversion.

Even for people with the visual capability to read, the process can often cause too much strain to be of any use or enjoyment. With Text-to-Speech, people with visual impairment can take in all manner of content in comfort instead of strain.

1.4 Aim and Objectives of Study

The aim of the study is to Design and Implement a PDF To Audio System. In achieving this aim, the following specific objectives were laid out as follows:

1. To design and implement a Speech synthesizer that converts text to audio.
2. To design and implement a System that can read out text in any frequency that user specifies.
3. To design and implement a speech synthesizer that can read out text in both female and male voices.

1.5 Significance of Study

The following are the relevance of this study, which are stated as follows:

1. The application will build a platform to aid people with disabilities especially on reading and also help get information easily without any stress.
2. The project could also help children learn how to pronounce words and how to read.
3. The study will serve as a foundation and guide to other research students interested in researching on Text-to-Speech systems.

1.6 Scope of the Study

The study focuses on the Design and Implementation of PDF to Audio System using web based programming languages. The PDF File will be imported and read via the browser.

1.7 Limitations of the Study

During the course of this study, many things militated against its completion, some of which are:

1. Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
2. Research material: availability of research material is a major setback to the scope of the study.
3. Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
4. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).

1.8 Definition of Terms

Learning Objects: In the context of this research, a learning-object-is-a-resource with a clear educational-application. It is in digital form − examples: a Microsoft Word Document or a PDF document.

Catalog: This research applies the word ‘catalog’ as a container that presents all the SICT projects logged/stored in an organized tabular format, showing relevant information about each project. It can be compared to a library catalog containing all the information about books − their titles, author, number of pages, published year, ISBN etc.

Repository: A repository (in this case; SICT repository) is an archive, storehouse or container that allows storage, cataloging, accessing all SICT undergraduate projects and thesis, and viewing each object’s content.

Identifier: An identifier is simply a unique identity attached to one object, it aids referencing such object directly when its identifier is requested. An identifier can be a serial number, identity number (also written as ‘ID’) or an index number.

Object: An object in the context of this research refers to a project record returned by a database − queried using an Object Oriented Programming (OOP) approach. An object (i.e. a project record) returns or contains the project topic, student name, abstract, year of project submission and the date and time the object record was created.

Database: A database is a repository that allows storage, retrieval and manipulation of data. A database can be used efficiently with the aid of a Database Management System (DBMS) − a set of tools that allow storage, access, retrieval and maintenance of data stored in a database, examples of DBMS include XAMPP, WAMP, LAMP and AppServ to mention a few.

Web-Browser: A web-browser, internet browser or browser is software program that interprets the codes written in markup languages in graphic and visual (like images, text, audio or animation) form. This allows users to easily request and access a website or to search for information through a search engine (either Google, Ask, Bing and AOL among others).

Keyword: A phrase or just one word that is used to search for a certain result or set of results.

User: A user is system, application, request or person that can use a computer or software to perform a specific task.

Metadata: A set of data that describes and gives information about other data.

Dataset: A collection of related game plans of information that is made out of disengaged segments however can be controlled as a unit by a PC.

Relational Database: A database composed to see association among relations of information delineates tables from which data can be gotten to or reassembled in different courses without rearranging the database tables.