36 CFR Part 1193 Telecommunications Act (Section 255) Accessibility Guidelines - Preamble

Paragraph (f) Prevention of visually induced seizures (Section-by-Section Analysis)

Comment. The NPRM suggested that the flash rate for visual indicators be set at or below 3 Hz, based on research for visual fire alarms, and asked (Question 8) whether this value was appropriate. The Epilepsy Foundation of America suggested that the value be reduced to a maximum 2 Hz, based on recent suggested changes to ADAAG and the ANSI A117.1 accessibility standard. The Trace Center also suggested the 2 Hz lower end but pointed out that some visual characteristics of video screens, for example, could not achieve that level. Trace presented data to indicate that a range of frequencies should be excluded between 2 Hz and 70 Hz.

Response. The provision has been revised according to the suggestion from Trace.

The NPRM also asked (Question 9) whether a similar provision should be included for seizures induced by auditory stimuli.

Comment. Those comments which addressed this issue said that the data are limited and that the responses seem to be very individual. At this time, there appears to be no good information on whether there are frequencies which should be avoided. The Massachusetts Assistive Technology Partnership encouraged the Board to conduct research on this issue. Trace Center noted that the provision for audio cutoff would help alleviate the problem by allowing a person with such a disability to insert a plug and cut off any external auditory cues. Since another provision of the guidelines would require the information to be conveyed visually, the person should be able to operate the product.

Response. The Board has not added a provision at this time but will seek further information on seizures induced by auditory stimuli.