Mass. Gen. Laws ch. 6 § 191
As used in sections one hundred and ninety-one to one hundred and ninety-nine, inclusive, the following words shall, unless the context clearly requires otherwise, have the following meanings:
"Commission", the commission for the deaf and hard of hearing.
"Commissioner", the commissioner of the commission for the deaf and hard of hearing.
"Deaf", a condition of or person with severe or complete absence of auditory sensitivity where the primary effective receptive communication mode is visual or tactile or both.
"Deaf community", a cultural minority with distinct modes of visual and tactile communication, languages and social mores.
"Hard of hearing", a condition of or person with some absence of auditory sensitivity with residual hearing which may be sufficient to process linguistic information through audition with or without amplification under favorable listening conditions, or a condition of or person with other auditory handicapping conditions.
"Late-deafened deaf", a deaf person for whom spoken language is the primary and preferred mode of communication where supplemented by other visual or auditory enhancement modes. The term "Late-deafened" shall mean that the onset of hearing loss occurred after the individual acquired full spoken language competence.
Mass. Gen. Laws ch. 6, § 191