The aims of this study were to explore expressive vocabulary growth rates of children who are deaf or hard of hearing (DHH) during critical periods of brain development (birth to 3 years) as well as the factors that influence the trajectories of vocabulary growth in these early years of development. Of primary interest was the effect of intervention frequency on expressive vocabulary growth.
Hierarchical linear modeling was used to investigate trajectories of expressive vocabulary growth using multiple measures of longitudinal vocabulary scores. A total of 417 assessments across 105 participants were analyzed to determine the average rate of lexical growth in a young population of children who are DHH receiving early intervention before age 3 years. Expected growth trajectories were constructed based on varying frequencies of intervention during critical periods of brain development.
Results indicated average growth rates of 5.21 new words expressed per week. Increased intervention hours prior to age 3 years was significantly associated with higher degrees of expressive vocabulary growth.
The findings of this study suggest that greater intervention hours received before age 3 years are associated with higher degrees of expressive vocabulary growth for children who are DHH.
Intervention and Outcomes of Children in Different Types of Listening and Spoken Language Programs
This study explores the impact of the type and dosage of listening and spoken language (LSL) services on speech and language outcomes in children with cochlear implants or hearing aids in two LSL programs. Identical demographic variables were collected across the two programs for use in the statistical analyses. Speech and language outcomes were examined at ages 3 and 5 using standardized test measures. At age 3, significant differences in LSL outcomes existed between programs for children using cochlear implants but not for children using binaural hearing aids. However, at age five, outcomes were similar between the different LSL programs for children with hearing aids and cochlear implants. Total hours of LSL services do not serve as a predictor of LSL outcomes at five years of age. However, early identification of hearing loss, early amplification, and early enrollment in a LSL program were highly influential factors affecting LSL outcomes at three and five years of age. Non-verbal IQ and maternal education levels also influence LSL outcomes. Children with earlier access to hearing technology and LSL intervention may need fewer hours of LSL services to achieve age-appropriate LSL outcomes. Overall, both of these LSL programs supported age-appropriate speech and language outcomes by age 5.
Face Coverings and Speech Perception in the Classroom
Effects of Face Coverings and Remote Microphone Technology on Speech Perception in the Classroom
Many schools are facing critical decisions in the age of COVID-19, including how best to facilitate learning while wearing personal protective equipment, such as face coverings. Children, especially children who are deaf or hard of hearing (dhh), are entitled to quality access to auditory information for speech perception and learning—even when their teachers are wearing face coverings. This white paper addresses the question of how and to what degree face coverings (with and without remote microphone technology) are affecting speech perception in the classroom. It is important for all teachers, especially for those who work with children who are dhh, to consider the listening environment for any particular child in their classroom. It is our hope that this research will contribute to ongoing considerations for supporting student learning in the time of coronavirus.
Expressive Vocabulary Growth and Frequency of Early Intervention
Expressive Vocabulary Development in Very Young Children who are Deaf of Hard of Hearing
This longitudinal study aimed to explore the expressive vocabulary growth rate of children ages birth to three years, who are deaf or hard of hearing (d/hh). An additional aim was to investigate hours of direct instruction received during early intervention as a factor that may contribute to the trajectories of expressive vocabulary growth in young children who are d/hh. Hierarchical linear modeling with growth curve analysis was used to investigate expressive vocabulary growth in a population of d/hh children using multiple points of longitudinal vocabulary data. A total of 417 assessments across the 105 participants were analyzed to determine the average rate of growth and to construct expected growth trajectories based on the amount of intervention services received prior to age three. Results indicated positive linear growth trajectories with an average growth rate of 4.75 new words expressed per week (approximately 19 words per month) for a child identified as d/hh by six months of age with no additional diagnoses and who received four hours of intervention per week. This growth rate was less than what can be expected for typically-hearing children. Additional hours of intervention positively contributed to expressive vocabulary rates for children under three years of age. This study recommends increased hours of intervention prior to age three which exceed current intervention guidelines.
Frequency of Early Intervention, Spoken Language, and Literacy Levels
Effects of Frequency of Early Intervention on Spoken Language and Literacy Levels of Children Who are Deaf or Hard of Hearing in Preschool and Elementary School
Language delays associated with hearing loss during infancy may have a negative impact on academic development throughout childhood. Early intervention provided by the Moog Center for Deaf Education prior to 36 months of age was quantified, and associations with later outcomes were examined for 50 students who are DHH representing Moog Center alumni. The objective was to determine whether the amount of early intervention (referred to hereafter as dose of early intervention received at the Moog Center during the time children were 0-36 months of age) contributed uniquely to outcomes in preschool (4–6 years) and in elementary school (8–14 years). Analysis of language and reading outcomes concluded that greater doses of early intervention were beneficial, even when other contributing factors such as degree of hearing loss, nonverbal intelligence, and age at first intervention were taken into account. Those children with poor aided speech perception scores in preschool exhibited the most benefit from early intensive intervention. Average language scores were within the expected range in comparison with hearing peers in preschool and remained within expectation when assessed an average of four years later in elementary school. The intensity of early intervention provided at the Moog Center contributed significantly to long-term development of language and literacy over and above the benefits associated with the age at which intervention was delivered.
Amanda Rudge, Ph.D. 