Monday, September 4, 2017 2:21:14 PM


Last updated on Wednesday, March 24, 2021 - 18:36 by AbdullahZubair
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The IBMTTS add-on is the new driver for NVDA to use IBM tts synths. This driver can also be used with Eloquence synthesizer, since both shares the same communication protocol (sdk). This add-on is the sum of all contributions of the older driver known as eloquence (all that could be found) with new improvements and updated compatibility. If you want to learn more including the complete background, head over to the dedicated article written by the developer of IBMTTS in our blog.


  • Voice, variant, rate, pitch, inflection and volume setting support.
  • Extra head size, Roughness, Breathiness parameters settings support. Create your own voice!
  • Enable or disable backquote voice tags. Disable it to protect yourself from malicious codes from jokers, enable it to do many fun things with the synthesizer. Safe fun guaranteed!
  • Rate boost. If the synthesizer does not speak very fast to you, then enable it and get the maximum voice speech!
  • auto language changes. Let the synthesizer to read texts in the correct language.
  • Indexing support. The cursor will never be lost when using read all feature.
  • anti crashing filter expressions. The driver filters known crashing expressions.


1. NVDA.

You need NVDA 2018.4 or later. This driver is compatible with python 3, So you can use it with future NVDA versions. Once NVDA with python 3 is released, this driver will no longer be compatible with python 2.7. Please use the latest NVDA versions. Its free!

2. IBMTTS synthesizer libraries.

IBMTTS is just the driver, it requires the library to function. Here we are providing the the library in the download section that you can import in the driver. For non-techies, we are also providing a package with the library already attached.


The following instructions are for those who want to get the origenal driver and add the library themselves. For others the ready-made package is available in the download section that you simply need to install in NVDA.

  1. Install it as an NVDA add-on.
  2. Then open NVDA dialog settings.
  3. Set the IBMTTS folder files in the IBMTTS category.
  4. Also in this category you can copy the external IBMTTS files into Add-on.

Please note: if the synthesizer is inside the add-on, the driver will update the ini library paths automatically. So you can use it on portable NVDA versions.