You are seeing this because we have detected a problem when the page you were browsing was trying to make use of the Speech Dispatcher tool.

Some versions of Speech Dispatcher comes with a bug where, even if the setup is covering all required packages as well as installing speech voices, the default configuration ends up with no working voice. This was identified and fixed upstream and versions after 0.11.2 should have the correction for sure. Your distribution might have backported the fix to older versions as well.

Error messages you may encounter

• “You can’t use speech synthesis because the Speech Dispatcher library is missing.”

Installing speech dispatcher should help.

• “You can’t use speech synthesis because Speech Dispatcher needs to be updated.”

Make sure the version from your distribution matches the below requirements.

• “You can’t use speech synthesis because the Speech Dispatcher library is broken.”

The library was found and is matching version, but somehow it lacks some features Firefox needs.

• “You can’t use speech synthesis because Speech Dispatcher won’t open.”

There is a problem trying to communicate with the service. Mostly due to Snap or Flatpak as mentioned below.

• “You can’t use speech synthesis because voices aren’t available in Speech Dispatcher.”

While Firefox has been able to access the Speech Dispatcher tool, its current configuration results in no voice being available for producing sound.

Firefox depends on a minimal version of Speech Dispatcher v0.8.2. Most Linux distribution provide packages, and you can find a couple of examples of how to install below.

Installing the Speech Dispatcher package

Debian / Ubuntu

You can install the tool with the Synaptic Package Manager. Selecting Suggested packages should make sure you end up with a completely working setup. Alternatively, from the terminal, use:

sudo apt install speech-dispatcher

Fedora

sudo dnf install speech-dispatcher speech-dispatcher-utils

Checking Speech Dispatcher

You should try and make sure that the following command is able to output sound on your system. If it does not, then it suggests something is wrong with your setup, and you cannot expect Firefox to be able to use it for speech synthesis. If it is working, you should hear the word “hi” spoken.

spd-say hi

Failure to open Speech Dispatcher

Depending on your system configuration (including but not limited to usage of Snap or Flatpak packages but ), you might also hit a specific error case where Speech Dispatcher won’t open. This means that while Firefox has been able to find the required library to make use of Speech Dispatcher, it is unable to communicate with this service. This could be because of a failure to start the service, or lack of support for a feature such as systemd socket activation (mostly relevant in the Snap or Flatpak packages).

The support for systemd socket activation is dependent on a release of Speech Dispatcher above 0.11.4; your distribution might have a backport to make this working on older versions. We recommend that you consult a support forum for your distribution for help with this.