Reading Vocabulary Knowledge of Hearing Impaired Children in Special Primary Schools in Vietnam

This research aimed to investigate the reading vocabulary knowledge of hearing impaired children (HIC) in special primary schools in Vietnam.
Reading vocabulary tests were developed to assess the reading vocabulary knowledge of 218 HIC from second to fifth grade at six special primary schools in comparison with 554 hearing children (HC) at two regular primary schools.
Target words for the vocabulary tests were selected from a representative word list in Vietnamese language textbooks in each grade of primary school. Each test included 18 words equally divided into nouns, verbs, and adjectives, and three difficulty levels: easy, medium and difficult.
Results showed that, in comparison to the HC of the same grade, almost all of the HIC had scores equivalent to the lowest score group, i.e. the lowest 25% of the HC. The HIC were likely to understand adjectives less well than nouns and verbs. When the HIC progressed to higher grades, they showed no vocabulary development, except for the vocabulary at the grade 2 level. Further analysis revealed that, like the HC, the vocabulary knowledge of the HIC influences their reading comprehension.
A unique feature of special primary schools in Vietnam was the age of the HIC who studied in the same grade varied greatly. However, except for grade 5, there was no relationship between the ages of the HIC and their vocabulary knowledge. Similarly, the hearing levels of the HIC were not related to their vocabulary knowledge.
In general, as it has been documented in the research throughout the world, the reading vocabulary knowledge of the HIC in Vietnam was much lower than that of the HC. The HIC showed no development of vocabulary knowledge when their ages increased.