Does the teacher’s voice affect children’s language processing and test performance?
A short summary of two papers:
Only three published papers have explored the effect of the teacher’s voice on children’s language processing. In the current school debate on sound environment and the teaching occupation, the aspect of the teachers’ voice is important to bring forward. In the following two papers are summarised: one by Rogerson & Dodd, from 2005: Is there an effect of dysphonic teachers’ voices on children’s processing of spoken language? and a paper recently accepted for publication by Lyberg Åhlander V., Haake M., Brännström J. K., Schötz S. & Sahlén B Does speaker’s voice quality influence children’s performance on a language comprehension test?
Both papers are based on the fact that the teacher’s voice is crucial for the communication in the classroom and that the voice is a central tool for teaching.
The main purpose of both papers was to investigate the effect a disordered voice has on children’s speech perception and performance. The papers both assume the hypothesis that a disordered voice puts greater demands on the processing of the adverse voice signal, leaving less capacity to process the actual content of the message. Rogerson & Dodd also aimed at investigating a relationship between degree of dysphonia and the effect on children’s performance. The paper by Lyberg Åhlander et al aimed at investigating the effect on the test performance of children’s cognitive capacities: working memory and executive functioning.
Both papers included children from mainstream schools. Rogerson & Dodd included 52 girls and 55 boys with a mean age of 9 years and 8 months. Lyberg Åhlander et al included 43 girls and 43 boys with a mean age of 8 years and 7 months. The children in Lyberg Åhlander et al were assigned to one of two groups after testing working memory capacity (WM) and executive functioning (EF).
In both studies the children were presented with a test material read by either a dysphonic or a typical teacher voice, and both studies controlled the signal by presenting recordings of the same female reading in ordinary and dysphonic mode (thus, avoiding individual differences in accent, prosody and articulation). There were some differences regarding test material and the distribution of the tasks. Rogerson & Dodd presented all children with videorecordings of a “teacher” reading three texts in typical, slightly dysphonic and dysphonic mode where after the children took a written test.
In Lyberg Åhlander et al., the groups of children were presented individually with either the dysphonic or the typical voice through PC loudspeakers where they had to match a picture to the sentence read by the “teacher” (using TROG-2).
Both studies showed a significant effect of the dysphonic voice on the children’s performance but with some noteworthy differences. The effect was larger in the study by Rogerson & Dodd and they found that even the slightly dysphonic voice affected the children’s performance. In Lyberg Åhlander et al., the effect was significant when the tasks became increasingly difficult.
The children’s auto corrections were also tracked and the results showed that the group presented with the dysphonic voice corrected themselves to a higher degree than the other group, even at easier tasks. There was also an association between the tests of cognitive capacity and the target test TROG-2, indicating that cognitive capacity may be important for processing a dysphonic voice especially when a child is approaching his or her limits
Conclusion and Discussion
Both studies show a significant effect of a dysphonic voice on children’s performance. The cognitive capacity seem important when the task gets more difficult. More resources are needed for processing of the task when the child simultaneously needs to shut out the dysphonic voice and even a slightly dysphonic voice affects the children’s processing of a message. The differences between the results may partly, be assigned to the differences in the tasks the children had to solve. However, the results speak for themselves.
Children are affected by a dysphonic voice which hampers their language processing and understanding. Awareness about how one’s own voice and communication can affect others needs to be addressed in the teaching profession. A suggestion would be to start with the teacher education programs!