To change the wpm conversion for speech-dispatcher with espeak is done in the espeak-generic.conf file, found in the speech-dispatcher modules directory (usually /etc/speech-dispatcher/modules/ or /usr/local/etc/speech-dispatcher/modules/ if neither, you changed and should know). There should be a section in this file that refers to value conversions (pitch, volume, rate), it is in this section that you need to alter things. Speech-dispatcher does the conversions by multiplying its value, and adding a value, its values for rate are between -100 and 100. Change the rate multiply value, if you wish to have a greater spread of values (i.e. steps between each speed setting), use a value greater than 100, or for smaller steps (probably shouldn't be done for espeak, and I don't think it would actually do much, as this will lead to decimal values that then should be rounded) then use lower than 100, or use 100 for speech-dispatcher to work in wpm. Now alter the rate add value, should be above 100, or negative values could be sent to espeak, but you will probably want this to be about the speed you actually want.
