The iPhone may not be any more accessible to those with hearing or speech impairments, but it's now more affordable on a monthly basis. AT&T has introduced a $40-per-month Text Accessibility Plan [1] available through the company's National Center for Customers with Disabilities. The plan includes unlimited SMS messaging and unlimited EDGE data, along with 40-cent-per-minute voice usage and Apple's Visual Voicemail.
Customers who qualify can purchase and activate an iPhone as if they were applying for a regular service plan, and then contact AT&T's center to have the plan changed to this new offering.
This plan is essentially the same as the most expensive messaging package [2] available as an add-on for existing AT&T customers who upgrade to an iPhone - that unlimited messaging plan also costs $40 per month - without any requirement for a voice plan. For other customers, AT&T requires at least a $40-per-month voice calling plan, which would be the equivalent of 100 minutes of calls made per month using this new offering.
A separate iPhone TTY (teletype) adapter ($19) allows the use of standard TTY equipment for relay calling, although relay calling requires the use of voice minutes. Apple documents its iPhone accessibility features [3], although the iPhone lacks a common feature ensuring hearing-aid compatibility that is not yet mandated by the U.S. Federal Communications Commission.
The FCC apparently started enforcing a requirement on 18-Apr-08 [4] after cellular telephone carriers failed to hit a mark that 50 percent of all cell phone models offered have one or both of two forms of hearing-aid compatibility.
[1]: http://www.wireless.att.com/about/disability-resources/text-accessibility-plan-for-iphone.jsp
[2]: http://www.apple.com/iphone/easysetup/rateplans.html
[3]: http://www.apple.com/accessibility/iphone/index.html#tty
[4]: http://www.fcc.gov/cgb/consumerfacts/hac_wireless.html