Have you ever noticed the “Text to Speech” function in Windows 7? It can be configured in “Speech Recognition” Control Panel applet.
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.
Back to the days of Windows XP, Microsoft merely included Microsoft Sam as system default voice; other languages have to be downloaded individually. Unfortunately, the sound quality of them are rather poor, or say, disgusting – from my point of view. Of course, you can purchase and install excellent third-party voices, but they usually expensive.
In Windows 7, things are a little different. There are usually two voices built into system – Microsoft Anna for English, and a localized voice for the current language. You will obviously find that the quality is much better than before.
After having the proper voices, you are ready to use the TTS technology to convert text to speech. Now the task is, installing suitable TTS software.
In fact, both Windows XP (English Version Only) and Windows 7 has Microsoft Narrator to read the screen, but it’s too simple in functions. You can read this article How to read text from dialog box for more information about it.
Windows Narrator
In this article, I will introduce two more powerful TTS converters. I’m sure they will cover almost all your needs, hope you like them.
TextAloud is Text to Speech software that converts your text from MS Word Documents, Emails, Web Pages and PDF Files into natural-sounding speech. You can listen on your PC or create audio files for use on portable devices like iPods, PocketPCs and CD players. TextAloud even has automatic iTunes/iPod syncing.
TextAloud
There are already many articles in Recipester about TextAloud. At first, you can use TextAloud to read text from a file or read text from a webpage. Then, you may need to convert documents to MP3 speech for use on portable devices. The whole story is too long? You can also split and convert text while converting text to audio files. What’s more, it’s easy to insert Pause and Voice Change while reading text file to speech…
Don’t you think it’s awfully powerful? But a slight disadvantage of TextAloud is, the excellent program is not free…
While TextAloud reads only text files and webpages, NVDA reads your entire screen.
NonVisual Desktop Access (NVDA) is a free and open source screen reader for the Microsoft Windows operating system. Providing feedback via synthetic speech and Braille, it enables blind or vision impaired people to access computers running Windows for no more cost than a sighted person. Major features include support for over 20 languages and the ability to run entirely from a USB drive with no installation.
NVDA
Although NVDA is awesome freeware, many people does not know it at all, so there seems no more tutorials about the program, except the official NVDA Documentations.
Want to know more about funny and useful software applications? Please comment this post to let me know 
I recommend Panopreter Plus (http://www.panopreter.com) to Windows 7 or vista users, The software reads text and converts the text to mp3 and wav files with the voice of Microsoft Anna, it’s simple to use. A free edition is available too.