Experimental manipulation of speaking rate for studying temporal variability in children's speech
Bruce L. Smith, Steven H. Long, Michael D. Sugarman · The Journal of the Acoustical Society of America · 1982
Children's speech typically exhibits both longer segment durations and greater inter- and intra-subject variability than the speech of adults. One hypothesis which has been proposed to account for the greater variability is that children have less-refined neuromotor control capabilities and do not move their articulators with the same accuracy that adults do. Another hypothesis is that children's increased variability is essentially a statistical artifact which occurs because of the greater range of durations likely to be associated with longer segment durations. In the past, statistical methods alone (e.g., “relative variance” and “coefficient of variation,”) have been used in an attempt to compensate for between-group duration differences when comparing variability in the speech of adults and children. In the present study, durational factors were also experimentally manipulated by having three groups of children (ages 5, 7, and 9) and a group of adults produce ten repetitions of a sentence at each of three different speaking rates: normal, fast and slow. Within- and between-group comparisons of variability under these conditions were investigated. Results will be discussed in relation to the above two hypotheses.