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The Evolution of Text-to-Speech Voice Assistive Technology

The Evolution of Text-to-Speech Technology
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Stephen Hawking is probably the first name that comes to mind when text to speech (TTS) voice assistive technology is mentioned. Hawking was diagnosed with a motor neuron disease known as amyotrophic lateral sclerosis (ALS) at age twenty-one, ultimately causing paralysis and confinement to a wheelchair, as well as an inability to speak. Thanks to the use of TTS voice assistive technology, Hawking has been able to communicate his genius for decades longer than thought possible. Hawking’s new voice was made possible by the DECtalk DTC01, which was adapted specifically for the theoretical physicist from technology first designed for automated telephone answering systems.

When asked why he continued to use the now-obsolete DECtalk when more natural sounding voices became available, Hawking always stated that he identified with the voice, and saw it as his own. This should not be surprising since Hawking and the sound of DECtalk DTC01 have become inseparable to most people, with even different yet similar sounding devices being commonly identified as Dr. Hawking. Last year, Hawking is said to have began using a new voice system, NeoSpeech‘s VoiceText speech synthesizer. However it seems that rather than using the more natural sounding voice that NeoSpeech offers, he has kept “his” voice, the sound of the original DECtalk.

Though Dr. Hawking’s input system is limited by his mobility (the use of cheek muscles and two fingers), this is not always the case. In most instances, TTS technology is used by people who have full use of their hands but lack verbal communication abilities, such as individuals with autism or those who are visually impaired and use the software to read. In these cases, the sound of the voice is more important than the text input, which also explains why most advancements have been made in TTS. These developments have drastically improved the quality of life for many individuals who would otherwise be without the ability to communicate.

There have also been huge advancements in the field of input as well, which assists people like Dr. Hawking, and even those who have no mobility at all. A study of brain wave activity, which was presented in 2009 to the American Epilepsy Society, showed that it is possible for people to input data into a computer (“type”) using only their minds. This is achievable by the use of electrodes implanted in the brain, electrocorticography (ECoG), and enhanced brain wave software.

“[Subjects] were asked to look at a computer screen containing a 6-by-6 matrix with a single alphanumeric character inside each square. Every time the square with a certain letter flashed, the patient focused on it and a computer application recorded the brain’s response to the flashing letter. The computer software calibrated the system with the individual patient’s specific brain wave patterns. When the patient then focused on a letter, the letter appeared on the screen.” (Source)

Brain wave technology is sure to change the lives of people like Erik Ramsey, a young man with Locked-In Syndrome, a condition in which a patient is aware and awake but cannot move or communicate due to complete paralysis of nearly all voluntary muscles in the body except for the eyes. This condition is caused by traumatic brain injury (like Erik), certain medical conditions (like ALS), and even medical overdose. Erik recently was able to use brain wave technology to speak three vowel sounds, hopefully soon moving on to full worlds, all done by thought.

Brain wave technology has already made it into the mainstream, appearing in children’s toys (such as the “Star Wars Force Trainer”) and video game designs. One of the aforementioned studies even used this technology to send the first brain-powered Tweet! TTS has also become a feature frequently used by many fully able-bodied individuals, such as the TTS enabled GPS systems. This is why it is always important to think about the technology we use everyday, and remember that sometimes the advancements we take for granted were made in order to give someone a better life.

Erik's Progress

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