Children who are deaf or hard of hearing (D/HH) benefit through universal newborn hearing screening. Early intervention can improve communication outcomes—but when an initial screening is for hearing, other problems may be overlooked until an astute clinician, therapist, or family member notes a lack of appropriate skill progression. Although comprehensive epidemiological studies are lacking, demographic reports suggest 40% of children who are D/HH will have an additional disability. Late identification of an additional disability in a child who is D/HH delays appropriate interventions. The combination of deafness and an additional disability is multiplicative rather than additive, complicating the goal of helping children to meet their full potential.
Understanding Developmental Delays
Risk factors for hearing loss can overlap with risk factors for developmental delays. Even children whose hearing loss is not associated with developmental concerns can still have other risk factors for developmental delays.
Risk factors for developmental delays include environmental exposures (lead), failure to thrive, maternal substance abuse (alcohol), environmental deprivation, and a family history of learning problems. Other factors are neonatal (low birthweight, premature delivery, and birth asphyxia), congenital infections, and meningitis. These last items also signify an overlap of risk factors for hearing loss.
Following is a description of methods for early identification of additional disabilities in children who are D/HH. Children develop at different rates, but most meet milestones within a known range. Understanding typical developmental benchmarks helps to identify development that is atypical for children who are D/HH.
Atypical Gross Motor Development
Children progress through gross motor skills in a fairly consistent pattern—93% of children who are D/HH without vestibular problems develop gross motor skills at the same rate as hearing children (see Table 1). The only exception is when a specific cause of the deafness affects balance or vision.
Monitoring for delayed milestones (see sidebar, "Atypical Gross Motor Development Patterns") or sensory integration concerns (see Table 2) is important. Children with cerebral palsy have not only delayed motor skills, but also atypical patterns. Children with motor delays or cerebral palsy may have normal or above-average intelligence.
Some children have low muscle tone, which can cause motor delays. These children seem somewhat "floppy." In children with motor difficulties, positioning can be important in the success of treatment and interventions. Children who require a lot of energy to stay upright may be unable to attend to communication-related tasks. A child needs good trunk control for respiratory control. Seating devices, positioning, and other adaptations for children with low muscle tone may promote more success in developing communication skills. Physical therapists are an excellent resource for identifying strategies to help children improve their functional motor skills.
Difficulties With Sensory Integration
Sensory integration is a theoretical framework for understanding how the brain develops the capacity to perceive, learn, and organize behavior. As the senses take in information, the brain processes and organizes it for responses. The sensory systems help establish arousal states, helping us attend, contributing to our emotional state, and promoting action on the environment. Many people have some difficulties with sensory integration, but not to the degree that affects daily function.
Children with sensory integration difficulties respond in atypical ways to their world. Different environments can prompt different responses. A professional who understands a child's difficulties can modify the environment and help the child develop more appropriate responses.
Children with difficulties in sensory integration need team collaboration that includes families, school, and an occupational therapist. Understanding a child's sensory needs and how to adapt the environment for success can be particularly rewarding.
Ruling Out Background Factors
If a child has—or seems to have—multiple challenges, several questions can be asked:
Has the child had consistent access to services? Have the therapeutic, technologic, and educational strategies been appropriate for the child's hearing? And has the family structure been able to support the child's developmental needs?
The following list describes some of the factors that influence development in children who are D/HH. If a child has had appropriate opportunities, yet exhibits slower development than expected, secondary disabilities may be present.
- Age of identification of hearing loss
- Audibility of speech spectrum
- Benefit from and consistent use of amplification
- Level of family involvement
- Quality of language exposure and educational services
- Presence of additional disabilities
- View of deafness as disability or culture
- Proficiency of family communication in chosen mode
- Deaf vs. hearing parents
- Grieving process of family on social/emotional development
Behaviors Related to Speech and Language Disorders
Determining if a child who is D/HH has language or speech disabilities beyond what can be explained through hearing loss is difficult. Developmental benchmarks for children who are D/HH can help determine if children with cochlear implants are making "adequate progress." However, for most hard-of- hearing children, evidence-based benchmarks to guide decision-making are lacking.
Language Learning Problems
For children with multiple disabilities, language learning may be both slower and qualitatively different than for typically developing children who are D/HH, as outlined in the sidebar, "Atypical Behaviors," on p. 28. For example, children with secondary disabilities may exhibit less efficient language learning processes than their peers. Such children may use adaptive strategies to deal with language that is hard to understand. They use partial linguistic (key nouns in the message) or nonlinguistic cues (situational cues, picture cues) for making sense of input, instead of fully processing the message. This behavior can be counterproductive to the learning of relational concepts and language rules. These children may require additional time to process basic messages. They may display inordinate difficulty understanding even basic questions.
Some children with comprehension deficits also demonstrate a "gestalt" learning style. Amy Wetherby noted that children using such an approach may show language production skills in advance of comprehension. The child may focus on intonation-oriented chunks of information, and use giant words or unanalyzed wholes ("wanna_cookie"). The child may rely on imitation as a language-learning strategy. This language-learning approach is observed in some children who progress on measures of auditory development, but show very slow language progress in spite of advancing listening skills.
Vocabulary Learning Strategies
Children who are D/HH with additional disabilities also may differ in vocabulary learning strategies. Typically developing word learners become more efficient as their vocabularies grow, and usually accelerate their word-learning rate. Typically developing D/HH children expand the lexicon across semantic classes, and often learn to fast map new words once their vocabulary is a sufficient size. Atypical D/HH learners may demonstrate inordinate difficulty with some semantic classes (e.g., locative relations, questions) and not others (basic nouns). Reliance on multiple trials for learning may persist, and the child may need generalization trials to extend meanings beyond the learned context.
Vocabulary learning difficulties may appear as frequent semantic errors in expressive language. Semantic errors may indicate that a child has stored lexical representations in a disorganized manner. The student may find basic classification skills challenging. As a result, the child may struggle to recall words previously learned. These children may have inordinate difficulty with tasks that require manipulation of concepts without contextual support (i.e., tell how an airplane and car are alike).
Often children with additional disabilities are placed in total communication programs, where visually supported language helps the child acquire and recall words and concepts. However, these children may have difficulty integrating multiple simultaneous messages. Children in this situation may sign one word and attempt to say a different one. It is important to determine if children in this circumstance benefit from chaining of inputs (e.g., sign alone, then spoken alone, then together) or primary use of the visual mode as a way to support receptive and expressive performance.
Children with atypical expressive language abilities may be able to talk about present events, but may show considerable difficulty distancing from the immediate context or topic. They may struggle with the production of simple narratives about immediate past events. Challenges at the level of language organization may be suspected if a child's narrative attempts include: frequent false starts and revisions, sequencing errors, deletion of subjects, and problems with basic grammatical relations.
These children may have inordinate difficulty with tasks involving higher- order thinking. Clinicians may become concerned about a child who is D/HH when the child comprehends far more than he or she can express. A major gap between these domains may result from difficulties in the oral-motor or fine-motor domains, with the possibility of praxis influencing expressive development.
Motor Speech Problems
For a child developing spoken language, a motor basis for production difficulties may be seen in: difficulties with chewing and swallowing; presence of drooling; difficulty with automatic lip closure or lingual mobility; oral asymmetries; difficulties coordinating speech movements; prolonged use of simple syllables and restricted number of consonant sounds; and prolonged use of open syllables and difficulty with multiple syllable words.
Motor difficulties also may interfere with sign development for some D/HH children. Such difficulties may express themselves in six areas: isolated signs and simple phrases that are poorly articulated (by 3 to 3.5 years of age, most deaf children produce intelligible signs); difficulty isolating fingers to form handshapes; errors in sign orientation or movement; difficulty with bilateral coordination; problems with signs that require crossing of the midline; and problems with smooth coordination of multiple signs in a message.
Autism Spectrum Disorders
Some D/HH children demonstrate characteristics of autism spectrum disorders, but without collaborative teamwork, the diagnosis can be difficult. Autism experts may lack familiarity with deafness and its developmental impact. Similarly, experts in deafness may have limited experience with autism and its developmental sequelae. Teams should work together to diagnose children with these combined disabilities.
Recent work by Wetherby and colleagues provides evidence-based guidelines for early identification of autism spectrum disorders (c.f., http://firstwords.fsu.edu). Experts in deafness should familiarize themselves with the results. Autism specialists might be consulted if several atypical behaviors are observed over time, including: limited appropriate eye contact, lack of shared enjoyment, reduced range of language functions (e.g., communicating to get basic needs met, but not for sharing events or social interaction), restricted interests in toys (e.g., limited symbolic play).
Clinicians should avoid making negative predictions based on test scores or discrete observations. Children and families are often resilient in unpredictable ways. Use the learning rates over time in response to well-planned, differentiated instruction as a guide.
It is natural for parents to compare their child's progress with other children. When a child who is D/HH is in a class with peers who are progressing more quickly, feelings of frustration can emerge for families. These families may benefit from contact with parent groups organized around the secondary disability, so that those unique needs may be put in perspective. Parents should consider the sage advice of Tom Jones of Gallaudet University, "Focus on the donut, not the hole." Often families make healthy adjustments to the child's multiple needs by celebrating every small step and milestone; they recognize how small steps eventually become large ones.