Audio File Options

Setting Audio File Options

• From the menu, select Options -> Voices and File Options
• Select the File Options panel.

The following fields are available on the File Options panel

Field Name	Description
Audio File Format	Select from WAV, MP3 or WMA
Bit / Sample Rate	This setting is normally used to determine the quality of MP3 and WMA files generated by TextAloud.
Write to File Speed	This setting applies only for SAPI4 voices, and determines how much processor is dedicated to WAV file conversion. Higher values result in faster conversion. See Note below about setting this value too high.
Output File Directory	The directory where audio files are written.

 

Choosing a Bit / Sample Rate

You will notice that different combinations of Bit Rate and Sample Rate effect the quality of your MP3 and WMA files.  A general rule is to choose a Bit Rate or Sample Rate that gives you the best quality, but try to keep the Bit Rate as small as possible.  Smaller Bit Rates equate to smaller audio files and faster encoding time.

When choosing a sample rate, it is important to remember that high quality digital speech can be produced at much smaller sample rates than digital music.

If you're planning to copy MP3 or WMA files to a hand-held device (like an MP3 Player), you may also need to check if your device requires a particular audio format.  Some players, designed for digital music, only support sample rates in the 44kHz range, and may also require Stereo instead of Mono audio files.

Encoding in Stereo will significantly increase your audio file sizes and encoding times.  Since the originating TTS output is truly Mono, it is best to use stereo encoding only if required by the portable device you're using.

The following table provides recommended settings for various voices.

Voice Engine	Recommended Bit / Sample Rate
Microsoft Voices	32kpbs, 22.05kHz, Mono
Lernout & Hauspie	16kpbs, 11.02kHz, Mono
8kHz AT&T Natural Voices, 8kHz NeoSpeech	16kpbs, 16kHz, Mono
16kHz AT&T Natural Voices	24kpbs, 16kHz, Mono
Cepstral Voices, 16kHz NeoSpeech Voices	24kpbs, 16kHz, Mono

 

Tips

• Most good CD burning software can burn audio CDs from WAV and MP3 files generated by TextAloud. If you do not have audio burning software, check out MP3 CD Burner at http://www.nextup.com/partners.html
• If you have Windows XP, Windows Media Player has built in burning. You just go to the copy to CD or Device item on the left side of windows media player, Drag in the TextAloud created files, then click the record button in Windows Media Player.

Notes

• If you're creating WAV files using SAPI5 voices, the Bit / Sample Rate dropdown list can be used to set the WAV file sample rates.  This option is not supported with SAPI4 voices, and is only available if SAPI Version is set to "Use SAPI5 Only".
• On some machines, setting the value for Write To File Speed too high may cause WAV file conversion to interfere with other applications on the machine, and may also cause corrupt WAV files to be generated.  We recommend starting with a value of 10x, and increasing the value gradually.
• The SAPI version mentioned on this page can be set on the Engines / Voices options panel.

Related Topics

Getting Better Voices