Text translation holds other challenges, and they vary by language, Sankar said. A common way to refine that process is a statistical approach, comparing large documents that humans have translated between two languages. But some pairs of languages have more translated documents available than others, so accuracy varies, he said.
Where real-time translation is closer to reality is in specific subject areas such as business, technology, law and travel assistance. For example, transcribing and translating prepared speeches that cover certain subjects is about 90 percent accurate in real time now, Sankar said. Impressively, Samsung says S-Translator's vocabulary is not limited to travel subjects.
Another caveat about translation is that supporting a long list of languages doesn't necessarily mean the system can translate freely among them all. Because the process relies on translations that have already been done, what matters are language pairs. In S-Translator, U.S. or U.K. English can be mutually translated with each of the eight other included languages: French, German, Italian, Latin-American Spanish, Brazilian Portuguese, Korean, Mandarin and Japanese. In addition, Korean, Mandarin and Japanese can be mutually translated among themselves.
For translation, S-Translator uses Samsung's own technology, not Google Translate or any other third-party platform. One limitation of the system's real-time interpretation is that it requires a data connection to an online translation server. Samsung isn't alone in this, according to Miller at Opus Research. That can be a problem for a feature that's often used, as in Samsung's example, while traveling.
"Unless they're doing stuff locally on the device, a lot of companies are ignoring the fact that having a data connection can sometimes turn out to be pretty expensive," Miller said. A rare exception is Jibbigo, a startup that makes an app for iOS and Android. Jibbigo comes as a free app that calls out to a server, but users can buy modules for offline translation of specific sets of languages. S-Translator on the Galaxy S4 does include translations of certain useful phrases built into the phone.
Both speech recognition and translation are steadily getting better, Sankar and Miller said. For one thing, software based on statistical models learns from each translation it does, Miller said.
Cisco sees real-time translation of videoconferences on the horizon, Sankar said, though within the bounds of something like a prepared, formal discussion between two diplomats.
"We believe here at Cisco that there will come a day when we will be able to have a Web conference with somebody on the other side of the world, across language boundaries, in a very natural conversational and fluent style," Sankar said. The bad news is, his forecast for that accomplishment is five to 10 years.
"You just have to exhibit patience and understand that it is not perfect, but they constantly improve," Miller said.