How does Stephen Hawking talk?

I understand that it’s actually his computer doing the talking, but how does he tell it what to say? I always assumed he just typed it in, but I saw him on a recent documentary and it appears as though he can hardly move his arms.

How does he do it?

And also, what exactly is wrong with him?

From this May:

How does Stephen Hawking’s ‘voice’ work?

You may find some worthwhile information on your question in that link.

Our search engine isn’t always the best, but sometimes it does the trick.

Welcome aboard!

Dr. Hawking is a victim of ALS, or amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease after the best-known public figure to have the disease. (Lou Gehrig’s Farewell)

ALS is a disease of the motor neurons–the nerve cells that control muscle function. The motor neurons themselves atrophy and fail to enervate the muscles which they normally would, causing a loss of muscle control. This loss of control starts in the limbs and moves toward the core of the body progressively. (Extremely summarized from Neurobiology of Disease. Frankly, there wasn’t much in there to begin with.)

ALS is always fatal, though Dr. Hawking has had the amazing good fortune to have remained alive with the disease for nearly forty years. Generally, victims succumb within two to five years of diagnosis.

You may want to check out the ALS Association for more information.

LL <–showing his Neuroscience roots.