Goto Settings...
Language and Input...
Make SURE that only the Keyboard you want to use is checkboxed.
Also leave a voice input checked.
Backout to Settings...
Apps...
Find the Keyboards you don't use and either:
'Uninstall' them...
=OR= if they are part of the System ROM,
'Disable' them...
In some System ROMs, you can disable the apps ability to generate notifications via:
a (an already checked ) Checkbox, uncheck it.
You will not need root to use the above method(s)...
Hope this helps...
-Dejunai