AsTeR --Audio System For Technical Readings
"The advent of electronic documents makes information available in more than its visual form ---electronic information can now be display-independent," explains T. Raman, the blind mathematician who created AsTeR, a computing system that audio formats electronic documents to produce audio documents. "AsTeR can speak both literary texts and highly technical documents (presently in La)TeX) that contain complex mathematics."

Raman continues: "Visual communication is characterized by the eye's ability to actively access parts of a two-dimensional display. The reader is active, while the display is passive. This active-passive role is reversed by the temporal nature of oral communication: information flows actively past a passive listener. This prohibits multiple views -- it is impossible to first obtain a high-level view and then 'look' at details. These shortcomings become severe when presenting complex mathematics orally.

"Audio formatting, which renders information structure in a manner attuned to an auditory display, overcomes these problems. AsTeR is interactive, and the ability to browse information structure and obtain multiple views enables active listening