[Emacspeak] speech rate adjustment

[taro.kuriyama@xxxxxxxxxxx]

I re-installed emacs / emacspeak on a fresh Mac and found that the speech rate config doesn't seem to work. System: MacOS Venture; emacs 28.2 / emacspeak 57.

I've always had this speech rate in my emacs config: `(dtk-set-rate 350 t)`

Since somehow that line isn't working, I also tried adjusting these global rate variables in `emacspeak/servers/mac`:

# global speech rate
ttsState['speechRate'] = 350
ttsState['charFactor'] = 1.8

Modifying those two lines also seems to have no effect. Any suggestions on further troubleshooting? 

Thanks!
Taro