MacOS: Is it possible to import customized voice in "Announce the time"?
I did 2 things to handle similar requirement. Since my way is not a direct file import meanwhile required preknowledge on shell, I am not sure if it can resolve your problem. 

The 2 things:


a bash script prepared to let PC alarm in the customized voice. You can find my bash script here call bclock.sh then substitute my sound file path with yours: https://github.com/vjyq/bclock/blob/master/bclock.sh
a cronjob set up to make PC chime hourly. My cronjob cmd: 0 * * * * /Users/&lt;user-name&gt;/bclock/bclock.sh   # you could get &lt;user-name&gt; via $ whoami


You may find more how-to in my post: https://vjyq.github.io/bclock/

Hope this helps.