Beverly A. Timmons

SEX AS A FACTOR INFLUENCING SENSITIVITY TO DELAYED AUDITORY FEEDBACK

30 men and 30 women read paragraphs under no DAF and 5 different DAF conditions. No differences were found in reactions of men and women when DAF conditions were randomized. When DAF conditions were ordered, women tended to adapt significantly more than men.

Age, sex, and delay time as factors affecting reaction to delayed auditory feedback.

Five groups of 10 males and 10 females each, aged 5, 7, 9, 11, and 13 yr., recited a nursery rhyme under normal delay and 113-, 226-, 306-, 403-, and 520-msec delayed auditory-feedback conditions. Speaking rate and disfluency count changes from normal delay to each delayed auditory feedback condition were calculated as indicators of reaction to delayed auditory feedback. Analyses of variance and post hoc comparisons indicated that 5-yr.-olds reacted with greater change in rate at 520-msec. delayed auditory feedback than did older subjects. Five- and 7-yr.-olds were more disfluent at 413- and 520-msec. delayed auditory feedback than were older subjects. Sex differences were found in the 7-, 11-, and 13-yr.-old groups, using speaking rate as a measure of delayed auditory-feedback reaction. No significant sex differences were noted when disfluencies were used as indicators of delayed auditory-feedback reaction.

Delayed auditory feedback and the speech of stuttering and non-stuttering children.

25 male stutterers and 25 male non-stutterers matched by age and speaking task, read or recited under normal and 113-, 226-, 306-, 413-, 520-msec. delayed auditory feedback conditions. Changes in speaking rate and disfluency count from normal to each delayed auditory feedback condition were calculated as indicators of reaction to delayed auditory feedback. Using an analysis of variance of difference scores for speaking rate, no significant differences were found between stutterers and non-stutterers or among the delays. An analysis of variance of disfluency difference scores showed no differences between stutterers and non-stutterers. Significant differences in disfluency reaction among delay times were found.

Speech disfluencies and delayed auditory feedback reactions of stuttering and non-stuttering children.

25 male stutterers and 25 male non-stutterers matched by age and speaking task, read or recited under conditions of normal and 113-, 226-, 306-, 413-, and 520-msec. delayed auditory feedback. Disfluency counts were correlated with delayed auditory feedback reactions which were changes in disfluencies under delay conditions. Pearson product-moment correlations were negative and significant for the combined group of stutterers and non-stutterers under all delays used. Correlations for stutterers were negative and significant for 113, 226, 306, and 413 msec. delay. For the total group of non-stutterers, all correlations were negative and significant. Correlations for age groups within the stuttering and non-stuttering groups were also presented.

Physiological Factors Related to Delayed Auditory Feedback and Stuttering: A Review.

Delayed auditory feedback (DAF) generally produces speech disturbances in normal speakers and improved fluency in stutterers. Several theorists have proposed that the speech disruptions of normal persons under such delayed feedback are an analog of stuttering. Related research has linked delayed auditory feedback and stuttering to several physiological factors. A review of familial relationship, age, sex, stress, speech characteristics, and sound conduction is presented. A brief integration of the factors and directions for research is presented.

SPEECH DISFLUENCIES UNDER NORMAL AND DELAYED AUDITORY FEEDBACK CONDITIONS

20 male and 20 female adults, matched by age, read under conditions of normal and 113-, 152-, 200-, 253-, 307-, and 347-msec. delayed auditory feedback. Disfluency counts were correlated with delayed auditory feedback reactions which were changes in disfluencies under delay conditions. Pearson product-moment and Spearmans rhos were negative and significant for delay times of 113, 153, 200, and 253 msec. The Pearson product-moment correlation for 307 msec, was also negative and significant. Two groups of 11 adults were selected from the original sample on the basis of high and low initial disfluency counts. Their reactions to delayed auditory feedback were compared, using a 2-way analysis of variance with repeated measures (groups × delay times). Both main effects were significant but not their interaction.

Expectancy as a factor in reaction to delayed auditory feedback.

In Exp. 1, Ss were asked to read under normal and .2-sec. DAF conditions. 3 sets of instructions and statements about effects of DAF were used for groups of males and females. In Exp. 2, the same reading conditions were used. Ss were either given 1 of 2 pre-recorded models or no information prior to DAF experience. In both studies, no significant differences due to type of preparation for DAF were noted. Under the conditions used, DAF reaction seems unaffected by expectancy of Ss.

DELAYED AUDITORY FEEDBACK AS A FACTOR INFLUENCING RETENTION

Four groups of 20 Ss read difficult prose after which retention was measured with a multiple-choice test. Group 1 read under normal conditions and was tested immediately. Group 2 read under normal conditions and was tested after 24 hr. Group 3 read under 0.2-sec. delayed auditory feedback with immediate testing, while Group 4 also read under delay but was tested after 24 hr. All Ss reading under normal conditions obtained significantly higher scores than did the delayed groups. It was speculated that delayed auditory feedback may affect acquisition rather than retention.

Twins' Reactions to Delayed Auditory Feedback

10 pairs of identical and 10 pairs of fraternal twins, matched by age, spoke under conditions of 0.0-, 100-, 200-, 300-, 400-, and 500-msec. delayed auditory feedback. Length of spoken passages was controlled. Product-moment and intraclass correlations were calculated for speaking times and disfluencies. Significant Pearson rs for times were noted at 0.0 and 300 msec, for both groups and at 100, 200, and 400 msec, for identical twins, while fraternal twins times were significantly correlated at 500 msec. Difference scores were significantly correlated at 100, 200, 300, and 400 msec, for identical twins. Disfluencies were significantly correlated for identical twins at 400 msec. Data were combined with those of Timmons (1969) study, increasing subjects to 21 pairs per group. Intraclass correlations supported the contention that responses of identical twin pairs to delayed auditory feedback were more highly correlated than those for fraternal twin pairs.