Screen readers on Linux¶

Current status: Linux TTS integration is a stub. The speak() function logs text to the Python logger (lights_off.speak) at INFO level instead of calling a TTS engine. No speech is produced unless you configure a separate log consumer.

This page describes the current state and how to add Speech Dispatcher support yourself while waiting for an official implementation.

Current behaviour¶

lights_off/speak.py on Linux:

import logging as _logging
_log = _logging.getLogger("lights_off.speak")
def speak(text, interrupt=False):
    _log.info("speak: %s", text)

Manually adding Speech Dispatcher¶

Speech Dispatcher is the standard TTS middleware on Linux. It is used by Orca (the GNOME screen reader), Emacspeak, and many other accessible applications.

1. Install Speech Dispatcher¶

sudo apt install speech-dispatcher python3-speechd   # Debian/Ubuntu
sudo dnf install speech-dispatcher                    # Fedora

2. Install the Python binding¶

pip install speechd

3. Patch speak.py¶

Replace the Linux branch in lights_off/speak.py:

else:
    import speechd as _speechd
    _client = _speechd.SSIPClient("lights-off")
    _client.set_output_module("espeak-ng")
    _client.set_language("en")

    def speak(text, interrupt=False):
        if interrupt:
            _client.cancel()
        _client.say(text)

4. Start Speech Dispatcher¶

speech-dispatcher

Or it may be started automatically by your desktop session.

Orca¶

Orca is the primary screen reader for the GNOME desktop. It uses AT-SPI2 (Assistive Technology Service Provider Interface) to interact with applications. wxPython on Linux exposes AT-SPI2 accessibility information, so Orca can announce focused controls, but Lights Off's own speak() calls will not reach Orca unless Speech Dispatcher is configured as described above.

Contributing¶

If you get Speech Dispatcher working, please open a pull request to add it to the upstream speak.py. The pattern is already established — it is a clean else branch with no platform-specific dependencies at import time.