$ sudo apt-get remove espeak 

Uninstall espeak including dependent package

If you would like to remove espeak and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove espeak 

Use Purging espeak

If you use with purge options to espeak package all the configuration and dependent packages will be removed.

$ sudo apt-get purge espeak 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove espeak 

See Also,