Cochlear implanted children’s perception and comprehension of grammatical cues in speech

This study investigates the processing of grammatical cues in speech (case and verb-agreement) of normal hearing children (NH) and children with a cochlear implant (CI). The aim is to find out whether both groups of children not only perceive the different cues, but also make use of them in processing.

Therefore, we examined children’s comprehension of subject and object questions. In order to correctly interpret object questions (in which the object precedes the subject) in German, case (e.g. Welchen Esel fängt der Tiger ‘Which donkey is the tiger catching?’) and/or -in some events- verb-agreement cues need to be used (e.g. Welche Maus fangen die Frösche? ‘Which mouse are the frogs catching?’).

The acquisition of object questions is a long ride for NH children as they heavily rely on word order and interpret object questions incorrectly as subject questions. For CI children, the subtle cues may even be harder to detect and mastered, since their linguistic input is different in terms of length (less years) and reliability. Even though CIs provide relevant cues for the perception of speech (Svirsky, Robbins, Kirk, Pisoni & Miyamoto, 2000), previous research suggests that the comprehension of grammatical aspects of speech is more difficult for children with a CI (Nikolopoulos, Dyar, Achbold & O’Donoghue, 2004; Friedmann & Szterman, 2011).

Participants were 36 NH children (age 7;05-10;09, Mean: 9;01) and 33 CI children (7;01-12;04, Mean:9;07, bilateral < 3ys). As the main task, a picture selection task with eye-tracking was carried out to test children’s comprehension of subject and object questions. Two additional tasks were carried out; a picture selection task to test children’s comprehension of verb-agreement in sentences with a standard word order and an auditory discrimination task to test whether children perceive the differences with respect to case marking (e.g. ‘der’ vs ‘den’).

Overall the children performed well on the additional task on verb-agreement (CI: 86%; NH: 96% correct responses) and on case (CI: 90%; NH: 99%). These scores correlated with ‘Hearing Age’ and ‘Age at Implantation’. Considering only those CI children how scored like NH children on the additional tasks, their comprehension of object questions was still worse (CI: 66%; NH: 86%) and more time was needed to detect the correct interpretation.

To conclude, even though CI children perceive case and verb-agreement, their development of syntactic capacities to use these cues for comprehension still lacks behind.