We describe experiments in visual-only language identification, in which only lip-shape and lip-motion are used to determine the language of a spoken utterance. We focus on the task of discriminating between two or three languages spoken by the same speaker, and we have recorded a suitable database for these experiments. We use a standard audio language identification approach in which the feature vectors are tokenized and then a language model for each language is estimated over a stream of tokens. Although rate of speaking appeared to affect our results, it was found that different languages spoken at rather similar speeds were as well discriminated as a single language spoken at three extreme speeds, indicating that there is a language effect present in our results.
Jacob L. Newman, Stephen J. Cox