While the concept of reading rate or "speed reading" is probably familiar, readers of this report may not be familiar with the concept of auding rate or "speed auding." Essentially, auding rate refers to how well one can comprehend spoken passages presented at different rates of speech. For instance, a paragraph might be read aloud to a listener at an average rate of 150 wpm, and a comprehension test administered immediately. This procedure is then repeated for comparable materials presented at rates of 200, 250, 300, and 350 wpm. Changes in immediate retention comprehension scores are used to indicate the influence of speech rate on auding. Thus "speed auding" means auding rapidly presented rates of speech.

In their 1969 review of research on rate of auding, Foulke and Sticht concluded that, when various studies are considered collectively, the relationship that emerges is one in which rate of auding comprehension declines slowly as word rate is increased, up to a rate of some 275 wpm; beyond this the decline in rate of auding comprehension is faster. Subsequently, Foulke (1971) reported data suggesting that rate of auding comprehension declined more rapidly when a wpm rate of 250 was exceeded. Carver (1973b, Figure 4) reported reanalyses of Foulke's (1971) data which indicated that, for very difficult test items, auding comprehension dropped off rapidly at 300 wpm, while for less difficult items auding comprehension declined only a little over the range of speech rates from 125 to 400 wpm. In Figure 5 of the same article, Carver presents data of his own indicating that subjects' judgment of how well they understood spoken messages presented at various rates dropped off gradually for speech rates from 100 to 300 wpm, and then declined rather rapidly at rates beyond 300 wpm.

Carver also presented evidence (Figure 6 of his article) to suggest that a "threshold" for comprehending auding materials might be surpassed at speech rates as low as 150 wpm, depending upon how comprehension is measured (e.g., multiple-choice tests, judgments of understanding). However, in a subsequent unpublished paper, Carver (197 3c) presents additional data to suggest that, for college students, auding comprehension drops precariously when rates exceeding 300 wpm are presented. Thus, although research exists to suggest that auding comprehension may or may not decline at rates of speech less than or equal to 250-300 wpm, evidence is strong for suggesting that rates above these levels will almost certainly lead to rapid losses of information by auding.