Barcroft, J., Mauzé, E., Sommers, M., Spehar, & Tye-Murray,
N. (2025). Perception versus comprehension of bound morphemes in children who
are deaf and hard of hearing: The pivotal role of form-meaning mapping. Journal
of Speech, Language, and Hearing Research, 68, 1024-1037. https://doi.org/10.1044/2024_JSLHR-24-00271
Children who are deaf or hard of hearing (DHH) often
fall behind their hearing peers with language development, have reduced
vocabularies, and weaker syntax skills. In particular, morphemes (the smallest
parts of words that carry meaning) at the end of words are especially difficult
for DHH children. One factor contributing to this difficulty is that word-final
morphemes are often quieter when produced, and often consist of high frequency
sounds, which are commonly more difficult to perceive by DHH children. Many of
these morphemes are learned in part through hearing them in use, which may also
make learning them more difficult for DHH children.
Barcroft et al. discuss two factors that impact the
acquisition of these morphemes: input (i.e., the words the individual is
exposed to) and intake (i.e., the information processed by the individual).
Many DHH children might face compound difficulties with these morphemes due to
having reduced input (e.g., lower exposure to the morphemes) and reduced intake
(e.g., due to reduced ability to perceive the morphemes). Another consideration
is that there may be a discrepancy between perception and comprehension of
these morphemes. That is, some individuals might perceive (hear) the morpheme,
but may not actually comprehend (understand) its meaning.
In their paper, Barcroft and colleagues asked:
- How well can DHH children perceive morphemes?
- How well can DHH children comprehend morphemes?
- Do DHH children acquire these morphemes in a particular order?
- Is perception and/or comprehension in DHH children impacted by vocabulary size or modality (i.e., auditory only vs. audiovisual presentation of information)?
DHH children between the ages of 5 and 12 years
participated in a series of tasks including a bound morpheme assessment testing
the perception and comprehension of 4 types of morphemes (i.e., contractions,
plurals, possessives, past tense), and standardized vocabulary measures.
Barcroft et al. found that DHH children overall had
better performance on measures of perception than of comprehension, and that
higher performance with one type of morpheme did not mean high performance on
all morphemes. The authors found that DHH children with higher vocabulary
scores (i.e., those with larger vocabularies) did better with morpheme tasks,
and that there did not seem to be a difference between auditory only vs. audiovisual
information.
This research demonstrates the importance of
vocabulary knowledge for the development of other linguistic skills (i.e., use and
comprehension of morphemes), and shows the importance of connecting morphemes
to meaning to support comprehension. Barcroft et al. emphasize the need to
address both the perception and comprehension of morphemes in DHH children,
reminding us that access does not = understanding.
