_  _    __        ___    ____  _   _ ___ _   _  ____     _  _ 
| || |   \ \      / / \  |  _ \| \ | |_ _| \ | |/ ___|   | || |
| || |    \ \ /\ / / _ \ | |_) |  \| || ||  \| | |  _    | || |
|_||_|     \ V  V / ___ \|  _ <| |\  || || |\  | |_| |   |_||_|
(_)(_)      \_/\_/_/   \_\_| \_\_| \_|___|_| \_|\____|   (_)(_)

!! The update to Montere has made this workaround totally unnecceary. !!

!! This repo now exists for purely eductaional purposes and my own bragging rights !!

!! The update to Catalina and subsequent move to zsh has broken my script !!

TTSpeed

Increase macOS text-to-speech beyond what the slider under 'System Preferences -> Accessibility' allows

To be honest I just barely know enough to have cobbled this together, but it works!

step one

First, you'll have to download the repository. Then, you'll need to double click the archive to unzip it. Now, open the Terminal app located in Applications -> Utilities -> Terminal or simply press Command + space to launch Spotlight and type "Terminal" Enter

step two

Change directory (cd) to where the shell script is stored with cd Downloads/TTSpeed-master,

grant tts5000.sh permission to run with chmod u+x tts5000.sh,

and copy it into /usr/local/bin with cp tts5000.sh /usr/local/bin.

step three

Edit ~/.bash_profile in TextEdit with open -a TextEdit ~/.bash_profile

copy and paste the following lines, save, and quit TextEdit.

alias tts='tts5000.sh'
alias ttspeed='defaults read com.apple.speech.voice.prefs VoiceRateDataArray'
alias rstts='killall com.apple.speech.speechsynthesisd && killall SpeechSynthesisServer'

step four

execute the following command for the changes to ~/.bash_profile to take effect.

source ~/.bash_profile

alternate steps 1-4

this does everything above from the command line (just copy & paste it into terminal)

cd ~/Downloads
curl -JLO https://github.com/insasquatchcountry/TTSpeed/archive/master.zip
unzip TTSpeed-master.zip
cd TTSpeed-master
chmod u+x tts5000.sh
cp tts5000.sh /usr/local/bin
echo "alias tts='tts5000.sh'" >> ~/.bash_profile
echo "alias ttspeed='defaults read com.apple.speech.voice.prefs VoiceRateDataArray'" >> ~/.bash_profile
echo "alias rstts='killall com.apple.speech.speechsynthesisd && killall SpeechSynthesisServer'" >> ~/.bash_profile
source ~/.bash_profile
cd ~/Downloads
rm -rf TTSpeed-master.zip
rm -rf TTSpeed-master
say Your installation of TTS 5000 is Complete
cd
#enjoy :D

usage

Now simply run tts5000.sh followed by your desired value

Jamess-MacBook-Air:~ james$ tts 450
(
        (
        1835364215,
        202,
        450
    ),
        (
        1886745202,
        184844483,
        450
    ),
        (
        1835364215,
        201,
        450
    )
)
Congratulations! Your Text-To-Speech speed has been successfully changed to 450!
Jamess-MacBook-Air:~ james$ 

Shoulders of Giants:

https://groups.google.com/forum/#!msg/macvisionaries/HOR7NWxsDQA/15E4M_6zqLUJ

https://superuser.com/questions/1051883/speed-up-rate-of-text-to-speech-via-terminal

https://apple.stackexchange.com/a/333291

http://omgenomics.com/writing-bash-script/