Child language skills before and after cochlear implant activation: input from the mother and acoustic environmental contribution

Many studies have investigated the role of individual and environmental factors in language development in children with cochlear implants (CIs) (Majorano et al., 2016; Szagun & Schramm, 2016). However, few studies have provided a longitudinal description of children’s language development before and after CI activation. Objective. The purpose of this study is to examine the relationship between environmental factors (the mother’s input and the acoustic environment) and language skills in three children before and after CI activation. The specific aims are: 1) to investigate the relationship between characteristics of the mother’s input and the child’s language skills; 2) to assess the relationship between exposure to different acoustic environments and the children’s language development. Methods. Three mother-child dyads were recruited from the “Guglielmo da Saliceto” Hospital in Piacenza, Italy. All the sample were implanted patients who fulfilled the following criteria: 1) CI activation before 3 years of age; 2) bilateral sensorineural hearing loss; 3) exclusive use of oral language; 4) no syndromes; 5) participation in a hearing and verbal rehabilitation program; 6) Italian monolingual normal hearing parents. Table 1 summarizes the characteristics of the sample. Mother-infant interactions were assessed twice, just before cochlear implantation and three months after CI activation. Mother’s prohibitive phrases and facilitative language techniques (explanation, labelling, open and closed ended questions, directives) and children’s language production were considered. Moreover, sound environment data from data logging (speech-in-quiet and speech-in-noise) were considered. Results. The children displayed different linguistic profiles. The first child increased his canonical babbling by 33% and his variegated babbling by 5%. The second child showed a 16% increase of canonical babbling, while the third child showed no production increase. Meanwhile, the mothers of the first and second child displayed a slight increase in phrases of: explanation (5% and 1%, respectively); labelling (7% and 2%); open ended questions (1% and 0,5%) and a decrease in prohibitions (4% and 7%). The mother of the third child, though, displayed a reverse profile, with fewer explanations (2%), labelling things (1%), open ended question (3%) and more prohibitive phrases (3%). The first and second child spent more time in speech in quiet (28% and 29%, respectively), while the second and the third child were more exposed to a voice in a noisy environment (35% and 45%, respectively). Table 2 shows the data of child spontaneous production, mother's input and children’s time of exposure to different acoustic scenes. Conclusion. The data show that both mother’s input (higher use of explanations, labelling, open and closed questions associated with a decrease in directives and prohibitive phrases) and acoustic environment characteristics (larger amount of speech in quiet) are related to the language development of children with CIs. In addition, there seems to be a co-occurrence between the quality of maternal inputs and the type of environmental acoustic exposure (higher proportion of speech in quiet). However, this is a preliminary study and a larger sample should be observed in order to enhance our understanding of the specific contributions of environmental and individual factors.