Text To Speech - Custom Rate (not on the slider)

Solution 1:

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

Solution 2:

Just to add to the two existing answers, I'd add that you can also do the activity monitor commands in terminal, so you can skip a ton of steps. Doesn't seem like you even need to enter the code separately.

plutil -convert json ~/Library/Preferences/com.apple.speech.voice.prefs.plist -o - | python -c 'import json, sys;d=json.load(sys.stdin);[x.__setitem__(-1, 720) for x in d["VoiceRateDataArray"]];json.dump(d, sys.stdout)' | plutil -convert binary1 -o ~/Library/Preferences/com.apple.speech.voice.prefs.plist -

killall com.apple.speech.speechsynthesisd
killall SpeechSynthesisServer

Solution 3:

Thanks to this thread and others, I've cobbled together a bash.sh solution that enables you to change the value quickly via terminal.

check it out! https://github.com/insasquatchcountry/TTSpeed

In the README.md is a copy/past install script for people like me who aren't very shell savvy.