Babbling and consonant production in children with hearing impairment who use hearing aids or cochlear implants - a pilot study

Objective: To investigate early auditory prerequisites in relation to the use of canonical babbling (CB) and early consonant production in a heterogeneous group of children with hearing impairment (HI) and in comparison to controls with normal hearing (NH). Methods: Five children with unilateral or bilateral HI who used hearing aids (HA) (0;9-1;7 years) and six children with cochlear implants (CI) (0;10-2;0 years) were compared to data from 22 children with NH (0;10-1;6 years). Hearing age, type of HI and daily use of hearing technology (hours) was investigated in relation to CB ratio and consonant production. Analysis of babbling from video recordings during verbal interaction between a parent and child was independently performed by two observers. Intra- and inter-agreement were calculated. Results: Children with HI used less CB compared to children with NH. Less CB utterances and occurrences of dental/alveolar stops were found in children with HA who had a hearing age of 5 months and who used their hearing technology 5 h per day. The children with CI reached an expected CB ratio and consonant production after 8.5 months with daily fulltime use of CI. Conclusions: Even a mild hearing loss in early childhood may affect and delay the onset of important linguistic milestones like canonical babbling and consonant production. It was indicated that children with CI or HA might receive different attention and intervention services. Longer hearing age and full-time use of hearing technology may influence positively on CB ratio and consonant production in children with HI.