n.1. a periodic change in loudness produced by superimposing two tones with similar frequencies. For example, the loudness of a 500 Hz tone and a 503 Hz tone when sounded together will fluctuate three times per second—the beat rate. 2. the periodic change in amplitude produced by superimposing two sinusoidal signals that are relatively close in frequency. See also roughness.
n. a set of study methods developed on the basis of research in cognitive psychology. The set represents six steps required for acquiring information: preview, question, read, reflect, recite, and review.