Föreläsningar och seminarier Predisputationsseminarium: Anna Persson
Swedish children with moderate hearing loss – on the importance of monitoring auditory and early speech development the first three years
Doktorand Anna Persson
Enheten för logopedi
Institutionen för klinisk vetenskap, intervention och teknik
The overall aim of this thesis was to investigate the auditory and early speech development in a cohort of children born with moderate hearing loss (HL) who were amplified with hearing aids (HAs) before the age of six months, and to compare their development to a group of children with normal hearing (NH). More specific aims were to examine the impact of auditory variables on the early speech development in the children with HL and to validate a questionnaire of auditory development in the children with NH.
This PhD project consisted of four longitudinal studies. Participants included a cohort of children with moderate HL (n=11) and a reference group of children with NH (n=29). Data was collected with assessments of early speech development and auditory variables at the ages of 10, 18, 24 months, 2.5 and 3 years that were compared between groups.
Study I validated the Swedish version of the LittlEARS® Auditory Questionnaire (LEAQ) in children with NH.
Study II investigated HA use from first HA fitting til 3 years of age and the impact of hours of HA use on auditory development and functional performance.
Study III examined consonant production in babbling and early speech at 10 and 18 months and consonant proficiency at 3 years.
Study IV investigated expressive vocabulary of children with HL, comparing their number and complexity of words to children with NH between the ages of 18 months to 2.5 years.
The Swedish version of the LEAQ was found valid to use, albeit the construct of auditory behavior has less emphasis in the second half. Despite early fitting with HAs with seemingly sufficient levels of aided audibility, this cohort of children with HL showed delays in their consonant production in babbling and early speech compared to the children with NH at 10 and 18 months. At 3 years there was no significant difference between the groups on consonant proficiency. The number of produced words and their complexity was similar between the groups at 18 months but at 24 months of age there was a gap in size which increased even further at the age of 30 months, disadvantaging the children with HL. The most prominent auditory variable found to impact the outcomes on the early speech measures was hours of HA use, meanwhile age at amplification, scores on auditory development, and aided audibility showed weaker relationships with varying significance.
The findings from this thesis suggest that children with moderate HL need monitoring of auditory and early speech development to identify the children at risk of future delays. Challenges in early speech development may be alleviated by full-day use of HAs from first fit. Other areas in need for more attention and research on larger groups of children with HL are early consonant use in babbling, expressive vocabulary development and auditory functional performance in noise.