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/<user-name>/bclock/bclock.sh # you could get <user-name> via $ whoami

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

Hope this helps.