Almost constant updates and user evaluations for the thing to work as we see it. Most Federation types have them just in their communicator, but some people (Ferengi) have them implanted. You will often see words that are not translated from different languages, so users must have to specifically choose which words that it should not.

I've always wondered about the over-lay of the sounds and the lag time....as I would see those as being more disruptive than just a speak & translate function. Of course what will be lost is the tone of voice (at least it would be for humans). Who knows if the other ST species communicate non-verbally in such a high percentage as humans do.

~Jeordam