Text To Speech - Custom Rate (not on the slider) In System Preferences, under Dictation &amp; Speech, there is a Speaking Rate setting:



Is there a way to change the Speaking Rate to a value that is not on that slider bar? 

For example, if I want the speech rate to be faster than the maximum slider value, how can I do that? There's a way to make the terminal speak certain lines of text faster (e.g. say --rate 500 "hello world"), but I'd like it to be the system-wide setting.

Can this be set using something like default write com.example.apple.speech.rate 999?
I discovered that you can change the VoiceDataRateArray in ~/Library/Preferences/com.apple.speech.voice.prefs.plist

I just changed the value of Item 2 to a value of value 500 and rebooted.

Thanks to tyler over at https://groups.google.com/forum/#!topic/macvisionaries/HOR7NWxsDQA