Replace the gnome specific speech API gnome-speech with a desktop agnostic speech API, speech-dispatcher, to resolve speech service requirements for GNOME 3.0.

Release Note

GNOME accessibility technologies now use speech-dispatcher for delivering text to speech to users. Speech-dispatcher provides a flexible architecture for converting text into synthesized speech, with support for several speech synthesizers out of the box, such as espeak and festival. Several languages are also supported.


There are plans to deprecate bonobo for GNOME 3.0. The GNOME accessibility technologies currently use bonobo rather heavily to provide access to the GNOME desktop. The other areas that need addressing are discussed at

Speech-dispatcher is currently the best alternative, as it already works with Orca, and can be used with other accessibility programs in Linux, BrlTTY, speakup, and yasr. However in order to be a viable speech backend for GNOME accessibility technologies, and indeed Linux, some important changes need to be made to speech-dispatcher itself. This specification details the needed changes for speech-dispatcher to replace gnome-speech for GNOME 3.0 and beyond.

The work to transition GNOME to speech-dispatcher is expected to take from now till GNOME 3.0 is released. For Karmic/the 2.27 GNOME cycle, the focus will be on what is discussed in this specification, to get speech-dispatcher ready for use with gnome-orca, including enabling speech-dispatcher in Ubuntu. The next 6 months for GNOME 2.28/3.0 will be spent bug fixing, and creating additional GUI configuration tools to make configuration of speech-dispatcher easier. This work will be discussed in a future specification.


Speech-dispatcher already works quite well with orca, however there is some extra functionality that needs to be added before speech-dispatcher can be considered a usable and default speech backend for orca and other GNOME accessibility technologies. A full specification regarding the work that needs to be done for upstream adoption is documented here: Changes that are relevant to Ubuntu, but also apply to upstream, are documented in the following sections.

UI Changes

Code Changes


Test/Demo Plan

To test speech-dispatcher cunctionality, one can follow these steps to test various parts of this implementation.

To test the automatic loading of the speech-dispatcher server when a user wishes to have a text string spoken, one only needs to run the spd-say command with the text they wish to have spoken. For example "spd-say Hello World." should cause speech-dispatcher to speak hello world. In doing this, the speech-dispatcher server should automatically load and speak the text.

To test speech-dispatcher with gnome-orca, one should do the following:

NOTE: For both above cases, speech-dispatcher's audio output may break up occasionally. This is due to speech-dispatcher's pulseaudio output code, which is not currently performing as well as is required. A short term work-around should be implemented by the final karmic release. Long term, this code needs to be optimized, along with other parts of speech-dispatcher.

Unresolved issues




DesktopTeam/Specs/Karmic/GnomeSpeechReplacement (last edited 2009-09-28 01:47:42 by ppp121-44-47-53)