The Chaffee Amendment in 1996 addressed the concerns of accessibility. Below is an excerpt from http://www.loc.gov/nls/
(a) IN GENERAL–Chapter 1 of title 17, United States Code, is amended by adding after section 120 the following new section:
“SEC.121. Limitations on exclusive rights: reproduction for blind or other people with disabilities
“(a) Notwithstanding the provisions of sections 106 and 710, it is not an infringement of copyright for an authorized entity to reproduce or to distribute copies or phonorecords of a previously published, nondramatic literary work if such copies or phonorecords are reproduced or distributed in specialized formats exclusively for use by blind or other persons with disabilities.
(1) Copies or phonorecords to which this section applies shall–
“(A) not be reproduced or distributed in a format other than a specialized format exclusively for use by blind or other persons with disabilities;
“(B) bear a notice that any further reproduction or distribution in a format other than a specialized format is an infringement; and
“(C) include a copyright notice identifying the copyright owner and the date of the original publication.
“(2) The provisions of this subsection shall not apply to standardized, secure, or norm-referenced tests and related testing material, or to computer programs, except the portions thereof that are in conventional human language (including descriptions of pictorial works) and displayed to users in the ordinary course of using the computer programs.
” (c) For purposes of this section, the term–
“(1) ‘authorized entity’ means a nonprofit organization or a governmental agency that has a primary mission to provide specialized services relating to training, education, or adaptive reading or information access needs of blind or other persons with disabilities;
“(2) ‘blind or other persons with disabilities’ means individuals who are eligible or who may qualify in accordance with the Act entitled ‘An Act to provide books for the adult blind’, approved March 3, 1931 (2 U.S.C. 35a; 46 Stat. 1487) to receive books and other publications produced in specialized formats; and
“(3) ‘specialized formats’ means braille, audio, or digital text which is exclusively for use by blind or other persons with disabilities.”.
(b) TECHNICAL AND CONFORMING AMENDMENT–The table of sections for chapter 1 of title 17, United States Code, is amended by adding after the item relating to section 120 the following:
“121. Limitations on exclusive rights: reproduction for blind or other people with disabilities.”.