Delayed sidetone in relation to the reading of different materials.

Several studies were conducted with speakers reading short phrases aloud while experiencing one amount or another of delayed sidetone (0.0-0.30 sec). The phrases represented different numbers of syllables, different types of syllables, different numbers of phonemes, and first and second languages. Additional syllables and unfamiliar material consistently increased the reading time of the speakers disproportionately. The reading of syllables of two and four sounds was apparently more retarded by delayed sidetone than ones of three sounds. Two-sound syllables comprised of vowel-consonants required more time to read than ones comprised of consonant-vowels. The effect of additional phonemes, with the type of syllables held constant, added linearly in the reading time of the phrases. The syllabic characteristics, the length, and probably the familiarity of the material affected the reading time nonlinearly.