NTT DoCoMo is developping Mime SPeech Recognition, a system that uses electromyography to measure the electrical activity in facial muscles used when a person speaks.
3 electrodes have to touch some areas of the face to detect electromyography in the muscles.
After three years, the prototype can recognize the five Japanese vowels and now researchers are working on consonants, then they intend to tackle other languages.

Found in Infoworld