Perception Versus Comprehension of Bound Morphemes in Children Who Are Deaf and Hard of Hearing: The Pivotal Role of Form-Meaning Mapping.

Purpose: Bound morphemes are challenging for children who are deaf and hard of hearing (DHH) to acquire and to use successfully. The challenge arises in part from limited access to spoken word forms as a result of reduced audibility during perception, but successful comprehension requires access to both the morphological forms and the mapping between these forms and their meanings. This study investigated the relationship between perception and comprehension of bound morphemes in order to assess the impact of form-meaning mapping on performance.

Method: Seventy-eight elementary school-age children who are DHH were tested on their perception and comprehension of four bound morphemes: third-person -s, possessive -s, past tense -ed, and plural -s/es. During assessment, these appeared in sentences presented using both auditory-only and auditory-visual modalities. The assessment procedure dissociated (a) perception of form using a sentence repetition task from (b) comprehension of meaning based on responses to a two-choice picture discrimination task.

Results: Analyses both confirmed the reliability of the measures of perception and comprehension and revealed generally higher performance for perception over comprehension. Critically, correlations between perception and comprehension were mostly not significant. Secondary findings included that higher performance for one bound morpheme did not imply higher performance on others and a significant relationship between measures of vocabulary and performance on the bound morpheme tasks.

Conclusions: The findings of the study highlight the importance of distinguishing between perception versus comprehension of morphological forms. Successful comprehension requires form-meaning mapping, whereas successful perception requires only acquisition of form. Both theoretical and practical implications of the mapping component of speech processing are discussed, including the value of providing programs of auditory training that are meaning-oriented in nature.