...Grissom's mother was deaf and because of this, he knows sign language [20] and can lip read[21]. He inherited his mother's otosclerosis, a disease which nearly led to the loss of his hearing. But he underwent corrective surgery [22] and his hearing problems have never resurfaced.
Early episodes revealed Grissom to be a witty, enthusiastic and quirky scientist, who had some sense of humor (used to have a Big Mouth Billy Bass over his door). He flirted regularly and seemed to be constantly on a hyperactive state.[30][31]
Grissom gives Dr. Phillip Gerard (Raymond J. Barry) his mother's regards, in sign language (The Accused is Entitled)
However, when he began to lose his hearing, Grissom retreated into himself and lost a lot of the nerdy spark he once had. He became easily irritable and unapproachable.[32] After his surgery, he lightened up a bit, but he has never gone back to the whimsical science nerd he once was. . .
In addition to being somewhat of a polymath beyond his career training, he exhibits Asperger-like traits, and in a second season episode it is hinted that, in fact, he has Asperger's syndrome.[33]
about your saying "BUG MAN" for his nickname in the tv show!!! 
beautiful signing!
