MIT scientists, led by an Indian-origin researcher, Arnav Kapur have developed a computer system that can transcribe words that users say in their heads. The device called as ‘AlterEgo’ lets others hear the words you are thinking without you’re making a sound. The system consists of a wearable device and an associated computing system. The device in its present form looks like a curved bone hooked to one ear that touches the jaw on the chin and under the lower lip. Electrodes in the device pick up neuromuscular signals in the jaw and face that are triggered by internal verbalizations, but are undetectable to the human eye. The device is thus part of a complete silent-computing system that lets the user undetectably pose and receive answers to difficult computational problems.
According to the Indian-origin researcher, “this device cannot read your mind… The system does not have any direct and physical access to brain activity, and therefore cannot read a user’s thoughts…the wearable system reads electrical impulses from the surface of the skin in the lower face and neck that occur when a user is internally vocalising words or phrases”. Thus this new computer interface is totally hands-free and voice-free, but it doesn't read your brain waves either. Instead it relies on something called subvocalisation, or silent speech - the name for what you're doing when you say words in your head.