Results of multiple regression analyses for predicting auding ability at each of the four rates listed indicated that while the Best Trend Name Test was a poor predictor of performance at the slowest rates, its correlation and beta weight increased significantly with the fastest rate of speech, identifying it as a major source of individual variance in the comprehension of highly accelerated speech. Thus, the ability to efficiently conceptualize semantic relations among vocabulary items facilitates comprehension of more rapid rates of speech.

The role of conceptualizing ability in comprehending auding materials is also demonstrated by the fact that, even at rates of speech of from 125 to 175 wpm, high aptitude men do not learn as much from materials written at grade level 14.5 or 8.5 as they do from materials of grade 5.5 difficulty (Sticht, 1972). Thus the effects of difficulty level of material appear to represent conceptualizing rather than languaging (encoding and decoding conceptualizations into and out of forms for communication) difficulties at normal rates of presentation, although research does not rule out the possibility that higher grade-level materials may be more difficult to encode and decode for some individuals.

The role of conceptualization ability, or ability to "organize our thoughts," in comprehending auding messages presented at various rates is also evidenced by the differences in performance between "high" and "low" aptitude students. Sticht (1972) found that men of low verbal aptitude did not learn as much auding fifth-grade materials presented at 150 wpm as high verbal ability men did at 350 wpm. In another study (Sticht, 1968) it was found that low verbal ability men learned passages of 6th, 7th, and 14th grade level of difficulty as well by auding as they did by reading when materials were presented at 175 wpm, but in neither case did they do as well as higher verbal aptitude men. Thus "low aptitude" or "low verbal" intelligence seem more likely to represent conceptualization problems than problems associated with rapid encoding or decoding of concepts into language to send or receive ideas.

The point we are making is that performance on immediate tests of retention of information typically used to evaluate auding and reading ability at various rates of presentation reflects a combination of the ability to encode and decode information from the conceptual base into or out of spoken or printed representations of our concepts, and the ability to formulate and reformulate concepts in keeping with the message being sent (speaking) or received (auding or reading). Other things being equal, the former ability will interfere with performance when rates of information display exceed 300 or so wpm, while the latter ability will hinder or facilitate performance over all ranges of rates of presentation, and can be demonstrated by manipulating the difficulty levels of materials and the "mental aptitude" of the students. We are inclined at the moment to call the former a languaging problem, and the latter a conceptualizing problem.