PhD defence T.J. (Tjeerd) de Jong

Below is a brief summary of the dissertation:

Adequate perception of speech is crucial for children’s development. Hearing loss can significantly affect speech perception, both in word recognition and in intonation (prosody). This may limit the resolution of expressed speech and result in communication problems and in social and emotional setbacks. This thesis investigates the psychosocial burden children with hearing loss may experience and explores ways to early identify psychosocial difficulties. Also, we elaborate on the prosodic conveyance potential of children with hearing loss . Additionally, we describe which communication abilities may further possibly be affected by hearing loss and how these abilities relate to the social functioning and psychosocial well-being of children. In chapter two, by means of a systematic review, we found that in contemporary research still a substantial share of children with hearing loss are observed to experience psychosocial difficulties, and that better speech perception and language skills are associated with better psychosocial well-being. In chapter three, we found comparable results in the pediatric population of our Audiology department. This chapter also describes how a brief questionnaire could serve as a primary screening tool for psychosocial problems in this population. In chapter four, using a newly developed prosody test, we found that the prosodic expression of children with hearing loss is in many ways like that of children without hearing loss. The few differences that we found, suggest that acoustic contrasts between some emotions are smaller than normal when expressed by children with hearing aids or cochlear implants. Also, children with cochlear implants may be relying more on intensity than pitch in expressing emotions. In chapter five, we found that emotions expressed by children with hearing loss are well identifiable by adults and peers. This study also shows that the smaller acoustic contrasts found in chapter four are related to limitations in the identifiability of some emotions expressed by children with cochlear implants. In chapter six, we showed that in children and adolescents without hearing loss prosodic recognition and -expression are correlated and that prosodic recognition increases distinctly with higher age. In chapter seven, we found that multiple abilities required for communication, among which hearing acuity, speech perception, prosodic perception and language skills are interrelated, involving also quality of life and psychosocial well-being. This thesis highlights the ongoing psychosocial challenges that children with hearing loss experience. This thesis provides directions for using a brief screening tool for psychosocial difficulties in this population. This thesis provides directions for adequately investigating prosodic conveyance and shows its association with other communication abilities and psychosocial well-being. This thesis provides directions for future research on prosodic conveyance and may also aid in identifying more specific problems these children experience in the psychosocial domain.