There's more to the picture than meets the ear - Gaze behavior during communication in children with hearing impairment

Many children and adolescents with hearing impairment struggle to meet school demands. The difficulties can be traced to the characteristics of the hearing impairment, and to adverse consequences on language development, often overlooked in diagnostics and intervention. This thesis investigates the communicative ability of children and adolescents with bilateral sensorineural hearing impairment by studying verbal and nonverbal interactions with normal hearing peers. The study uses a referential communication task requiring the speaker to make relevant descriptions, and the listener to use verbal and nonverbal means to resolve uncertainties. Analyses focus on verbal questions and answers (paper 1), nonverbal gaze behavior in relation to the verbal production (paper 2 and 3), and the cognitive and linguistic factors influencing the gaze behavior (paper 4). The results yielded that:

- The structured and predictive conversational setting enables speakers to include unrequested information without compromising the partner’s understanding (paper 1).
- Gaze behavior is related to the production of verbal utterances, as shown by a higher probability of gaze to the conversational partner’s face when asking questions than making statements (paper 2).
- Participants with hearing impairment consistently exhibit higher probability of gaze-to-partner than peers with normal hearing (paper 3).
- Participants with hearing impairment and reduced phonological short term memory capacity show a doubled probability of gaze-to-partner, compared to peers with normal hearing (paper 4).

The findings express the multimodality of communication, and the need for multidisciplinary assessment and therapy. Implications include pedagogical adaptations to an increased use of nonverbal cues in children and adolescents with hearing impairment. The results highlight areas of phonology and conversational strategies to target for speech-language services, and call for an evaluation of nonword repetition as a clinical marker allowing earlier identification of children with hearing impairment at risk for persistent language impairment.