Already have it..
The prepaid phone company I use has been doing this at least since last summer when I signed up for their service. I have no idea how well it works, but they charge 35 cents a minute additional to use it.
Access to Real-Time InCall Translation
Have you ever talked with someone from another country and worry about how effectively you are getting your point across? Don’t have time to study another language several hours a day for months and months so you can check on your work orders from Japan? No need to worry about that anymore. Available exclusively on the RingPlus network, you now have the ability to speak almost 20 different languages on your RingPlus phone. Imagine being able to have an ongoing conversation with anyone in nearly any language.
All RingPlus Wireless services include our In-Call Cloud Translator. Just pick up the phone, dial any number, and when the other party answers, press ** on your keypad. Tell our cloud translator which language you wish to translate to, and then speak normally in your native tongue. Once you stop speaking, we'll automatically translate and playback the words you said to your partner in their native language. This is the future of telecom, and only available through our RingPlus Cloud.