On Mac you also need:
$ brew install portaudio
$ pip install pyobjc
Then use:
# pip install pyaudio
# pip install speechrecognition
# pip install requests gtts playsound
Note: On a M1 Mac you may need to use this command to install pyaudio
# python -m pip install --global-option='build_ext' --global-option='-I/opt/homebrew/Cellar/portaudio/19.7.0/include' --global-option='-L/opt/homebrew/Cellar/portaudio/19.7.0/lib' pyaudio
For more setup instructions also have a look here: