Nowadays, more and more people use text to speech software to improve their reading efficiency and save time. As an important component of text-to-speech technology, voices, that is, speech engines, are the lifeblood of text-to-speech software. Because text-to-speech software must invoke them into synthetic speech.

However, the default voices that ship with operating systems, for example Microsoft Sam on Windows XP, don’t sound very natural. Actually, you need to install more high-quality voices. Fortunately, there are many speech engines available on the Internet today, such as Microsoft Add-On Voices, Lernout & Hauspie TruVoice and TTS3000, AT&T Natural Voices, Cepstral, IVONA, etc. Most of these voices are better than the default on your system.

Here is a list of text-to-speech voices available on the internet.

Microsoft Mike, Maria –

Microsoft Mike and Microsoft Mary are optional male and female voices respectively with higher quality, available for download from the Microsoft website or other third-party text-to-speech related websites.

The most notable feature of these three is that there are SAPI 4 and SAPI 5 versions of them. SAPI 5 versions are only available on Windows 2000 and later Windows NT-based operating systems. As an exception, SAPI 5 versions of these voices cannot be installed on Windows Vista and Windows 7. SAPI 4 versions are more compatible. They can be installed and used on Windows 98 and all subsequent Windows operating systems.

In general, the higher the SAPI version, the better the quality.

microsoft anna –

Microsoft Anna is the default English voice included with Windows Vista and Windows 7. Microsoft Anna is a SAPI 5-only speech engine and is designed to sound more natural than the previous system default voice, Microsoft Sam.

This excellent female voice is based on the new Microsoft SAPI 5.3/5.4. So you cannot use it directly on Windows XP and there is also no standalone installer for this voice on the Microsoft website. The only way to use this fantastic voice in Windows XP is through Microsoft Streets & Trips. Microsoft Streets & Trips 2006 and later versions install voice and the new Microsoft SAPI on Windows XP computers for the voice directions feature.

Some third-party text-to-speech websites provide smaller repackaged Microsoft Anna installers for Windows XP users. However, it is incomplete and does not work correctly on Windows XP because the SAPI version of Windows XP is 5.1.

Cepstral Voices –

These high-quality voices take up less disk space (less than 50mb on average) than most premium voices, don’t use as much processor power, and are very fast when creating audio files.

AT&T Natural Voices –

An award-winning text-to-speech technology developed by AT&T Laboratories. Many believe that Natural Voices is the most natural sounding TTS available, the “highly scalable” multi-threaded technology can automate and add tremendous interactive and humanistic value to a wide variety of applications and projects.

IVONA Voices –

Human voices for your PC: Use the most natural text-to-speech voices ever heard for fun and work.

CereProc Voices –

High-quality voices for computers running Microsoft Windows XP and Vista/7. You can replace Microsoft’s default American English voices with a wide range of other accents and languages. CereProc Windows voices are compatible with Microsoft SAPI5, and all voices are 22khz for excellent clarity and naturalness.

Voices of Lernout and Hauspie –

Lernout & Hauspie Speech Products, or L&H, was a leading Belgian-based speech recognition technology company. This company released dozens of high-quality SAPI 4 voices in multiple languages, including ten American English voices and two British English voices.

In addition, Lernout & Hauspie Michael and Michelle are also optional male and female voices licensed from Microsoft by Lernout & Hauspie and available through Microsoft Office XP and Microsoft Office 2003 or Microsoft Reader.