Eloquence for NVDA

Eloquence synthesizer add-on for NVDA with full 64-bit support.

64-bit support

The Eloquence DLL is 32-bit only. This add-on launches a lightweight helper process (eloquence_host32.exe) that hosts the DLL and streams audio back to 64-bit NVDA over IPC. The integration is transparent — no additional Python installation or manual steps are required.

For development scenarios where the prebuilt helper executable is unavailable, the ELOQUENCE_HOST_COMMAND environment variable can be set to the command that launches a compatible 32-bit Python interpreter with host_eloquence32.py.

Eloquence on secure screens (logon, UAC, start-up)

NVDA does not copy *.exe files to its secure-screen configuration for security reasons, so eloquence_host32.exe is missing after you click "Use currently saved settings during sign-in" in NVDA's General settings.

The easiest way to fix this is the built-in button in the add-on:

1. Open NVDA Settings > Eloquence.
2. Click "Copy Helper to System Config (for Logon Screen)".
3. Accept the UAC elevation prompt.

Eloquence should now load on secure and logon screens. You only need to do this once per add-on update.

Building

Prerequisites

• Python Install Manager (.msix)
• 32-bit Python 3.13: py install 3.13-32
• SCons: pip install scons
• PyInstaller for 32-bit: py -3.13-32 -m pip install pyinstaller

Build steps

git submodule init && git submodule update   # fetch pronunciation dictionaries
python fetch_eci.py                          # one-time: download proprietary ECI.DLL + voice data
build_host.cmd                               # compile 32-bit host exe (only needed if host_eloquence32.py changes)
scons                                        # package everything into the .nvda-addon file

Note: scons validates that proprietary files and the host exe exist, but does not fetch or build them — steps 2 and 3 must be done first.