179. Telephone

Having examined the postal system and discussed important issues with regard to accessibility, it is now useful to turn to the telephone system. The telephone system provides many advantages over postal service. Chief among these is speed of information delivery and the interactive nature of the media. However, fundamental differences between the telephone and postal systems required that accessibility be addressed in new ways.

Basic accessibility to telephone services requires a connection to the telephone network. Universal service efforts were designed to minimize this hurdle. These efforts are described in the Universal Service chapter, below. However, as mentioned earlier, universal access requires that technologies provide services in a useful manner. Unlike mail services, the telephone system imposes significant constraints on the communications it supports.

Providing useful telephone services to hearing-impaired individuals has required specific measures to address these constraints. The Americans with Disabilities Act (ADA) mandates support for two technologies that provide telephone service access to the hearing impaired. Text Telephone Devices (TTY, sometimes know as TTD) support typed communication over the regular phone system. This helps overcome the telephone system?s basic requirement of audio data formats.

The ADA requires support for such devices in a variety of ways including mandatory availability at public phone areas, hotels, etc. However, TTY communication requires that both parties use the technology and exists as an add-on to the telephone system. This means that TTY availability does not guarantee that the hearing impaired can effectively communicate with other parties.