The say Command is not Working in High Sierra

I recently upgraded my MacBook to High Sierra (from El Cap). It appears I can no longer use the say command. When I enter a simple command

$ say -v "Alex" "Test"
[...hangs...]

$ sudo say -v "Alex" "Test"
Password:
[...hangs...]

My laptop hangs. Is this a known issue and are there known fixes? If not, does anyone know what next steps I might take in diagnosing this problem?

Bug?

I could tell something was wrong because the Speech section of the Accessability pane in System Preferences was stuck loading voices and the voice sample play button also did not work. I killed some speech and audio-related processes with some luck.

I was also able to reproduce the hang by using the -o option of the terminal say command.

Workaround without reboot:

Try killing speechsynthesisd after finding it with

ps ax |grep speechsynthesisd

or just kill it this way:

kill `pgrep speechsynthesisd`

Is normal audio output working otherwise? Do you have an “atypical” audio output device?

Open the Speech/Narration system preferences pane, there may be some internal data that is “stuck” that could clear out by loading / saving preferences from that pane.