The otolaryngologist's role in management of hearing loss in infancy and childhood

This article reviews the role of the otolaryngologist-head and neck surgeon-in the diagnosis and treatment of hearing loss in infants and young children. The otolaryngologist is well-versed in the anatomy, physiology, and pathophysiology of the auditory system, as well as the craniofacial syndromes that can involve the head and neck in combination with deafness. In this paper, the various causes of congenital hearing loss are described, as well as the steps required for proper diagnosis. Finally, surgeries used by otolaryngologists to treat childhood hearing loss, their indications, and outcomes, are discussed.     

Early amplification options

Children with permanent hearing loss have been remediated with hearing amplification devices for decades. The influx of young infants identified with hearing loss through successful newborn hearing screening programs has established a need for amplification resources for infants within the first six months of life. For the approximately two of every 1000 infants born who are identified with bilateral hearing loss [Mehl and Thomson, 1998, Pediatrics 101, p. e4], the use of amplification is commonly the first step in treating the sequella of their loss. The use of hearing aids, combined with early intervention, has been shown to significantly improve the speech and language skills of young children with hearing loss [Yoshinaga-Itano, 2000, Seminars in Hearing 21, p. 309]. Speech and language delays have contributed to compromised academic performance of school aged children with hearing loss [Johnson et al., 1997, Educational Audiology Handbook, Singular Publishing, San Diego]. Most hard-of-hearing and deaf children use hearing aids and other assistive listening devices every day throughout their lifetime and the life expectancy of a hearing aid is only five to eight years. The current challenge for pediatric audiologists is selecting and evaluating the available amplification to provide the best options for children and their families. Amplification technology has seen an explosion in growth the past few years and the options continue to expand rapidly. This article examines currently available amplification technology and reviews the selection criteria that may be used for infants and young children. Issues such as style, type, amplification features, signal processing strategies, and verification and validation tools are also discussed.     

The effect of a simulated hearing loss on performance of an auditory memory task in driving

Hearing loss has been shown to exacerbate the effect of auditory distraction on driving performance in older drivers. This study controlled for the potentially confounding factor of age-related cognitive decrements, by applying a simulated hearing loss in young, normally hearing individuals. Participants drove a simulated road whilst completing auditory tasks under simulated hearing loss or normal hearing conditions. Measures of vehicle control, eye movements and auditory task performance were recorded. Results showed that performing the auditory tasks whilst driving resulted in more stable lateral vehicle control and a reduction in gaze dispersion around the road centre. These trends were not exacerbated by simulated hearing loss, suggesting no effect of hearing loss on vehicle control or eye movement patterns during auditory task engagement. However, a small effect of simulated hearing loss on the performance of the most complex auditory task was observed during driving, suggesting that the use of sound-based in-vehicle systems may be problematic for hearing impaired individuals. Further research incorporating a wider variety of driving scenarios and auditory tasks is required in order to confirm the findings of this study.     

A test battery to assess intrasensory and intersensory development of young children.

The purpose of the study was to develop a battery of tests for use in evaluation of intra- and intersensory development of young children. A battery of 15 tests (4 visual, 4 auditory, 4 tactile-kinesthetic, and 3 intersensory) was administered to 109 normally developing 6- and 8-year-old and 32 slowly developing or learning disabled children. Interdependence of test items within each intrasensory and the intersensory category was determined; intercorrelations ranged from .00 to .78. Reliability estimates were also determined. Face validity was claimed for each item. The effects of age or developmental level on test performance were established. Based upon the interdependence of the tests, reliability estimates, and the capacity of the tests to discriminate among groups classified according to age or developmental level, a battery of 10 intra- and intersensory tests was proposed. The battery has 3 tests of visual perception-visual memory, dynamic depth perception, and size discrimination; 3 tests of auditory perception-auditory discrimination, auditory memory of related syllables, and auditory sequential memory of numbers; 2 tests of tactile-kinesthetic perception-tactile integration and movement awareness; and 2 tests of intersensory integration-auditory-tactile intergration and auditory-visual integration.     

Novelty responding and behavioral development in young,developmentally delayed children

This study examined whether or not a measure of information processing ability based on the discrimination of novel and familiar stimuli was related to behavioral development among developmentally-delayed infants. Two samples of handicapped infants were administered multiple measures of visual novelty discrimination and a battery of assessments which were representative of available measures of development in infancy. The results indicated that, as a group, the developmentally delayed infants were capable of discriminating novel and familiar stimuli. Also, correlational analyses indicated that responding to novelty was related to developmental accessment performance in both samples. This finding is consistent with previous data which indicates that novelty response measures are associated with important individual differences in young children.     

Perspectives on multisensory experience and cognitive development in infants with cochlear implants

Infants learn about their environment through sensory exploration, acquiring knowledge that is important for cognitive development. However, little is known about the sensory exploration of infants with profound hearing loss before or after they receive cochlear implants. This paper reviews aspects of sensory perception and cognitive development in hearing infants, discusses the implications of delayed access to auditory information for multisensory perception and cognitive development in infants who use cochlear implants, and suggests several new directions for research addressing multisensory exploration and cognitive development in infants with cochlear implants.     

Comparison of infant and adult P300 from auditory stimuli.

Event-related brain potentials (ERPs) using auditory stimuli were recorded from 5- to 10-month-old infants and normal young adults with a passive tone sequence paradigm. A P3 (P300) component was obtained which demonstrated the same central-parietal maximum scalp distribution for both subject groups. P3 amplitude was smaller and its peak latency longer for infants compared to those of the adults across all electrode sites. P3 measures remained stable across stimulus trials indicating that ERP habituation was not occurring. Evaluation of individual subjects suggests that the P3 can be elicited from infants with auditory stimuli in a manner similar to that from adults and may serve as a useful index for the assessment of cognitive function in infants.     

Behavioral assessment of auditory processing deficits in schizophrenia: Literature review and suggestions for future research

During the last decades, a considerable number of studies about auditory processing deficits in schizophrenia have been published, some of them using the term of Auditory Processing Disorder (APD). Due to heterogeneous methodology and inconsistent results concrete conclusions may not be straightforward. We focused on studies that used at least one behavioral test for the assessment of auditory processing in schizophrenia, in order to identify new evidence on auditory processing deficits in schizophrenia, and to consider fields for future research. 28 studies met inclusion criteria and are presented in this review. The articles were divided into three groups, those that implemented a test battery approach, those that used only Dichotic Listening (DL), those that used DL along with imaging or electrophysiology techniques. Most of the studies that implemented a test battery showed significant performance differences between patients and controls. This indicates APD presence. Due to the limited number of studies implementing a test battery, this is not conclusive. The majority of all studies that used a DL task showed that patients' performance or laterality was significantly lower than that of controls. Age, duration of illness, total and specific positive symptoms seem to affect significantly DL performance and auditory laterality. The results support the existence of various schizophrenia subgroups that differ in their auditory processing performance, and also have structural and functional specificities. Further research in the field is needed, especially studies that implement a test battery, and studies that examine possible correlations between clinical variables and auditory processing deficits.     

Measurement of attention and related functions in the preschool child

The goal of this review of the clinical and research literature is to identify, describe, and critique published methods for assessment of attention and related functions in preschool children (ages 6 and younger). The need for valid assessment of preschool children has grown dramatically in the past two decades following the implementation of special education services for infants, toddlers, and preschoolers under Public Law 99-457. At the same time, the number of preschool children presenting to clinicians for assessment of attention problems has grown at a steady rate. In contrast to assessment methods for school-age children, the availability of reliable and valid measures of attention for preschool children is much more limited. The majority of instruments developed to measure attention in preschoolers are described in the experimental literature, with fewer available commercially. Attention tests that can be appropriately used with children aged 3 and younger are scarce. Most preschool tests of attention report validity data involving sensitivity in contrasting clinical groups to controls, while the literature describing the utility of these measures in differentiating between clinical groups is much more limited. The review provides information on performance based tests (e.g., continuous performance, cancellation, auditory/visual span), as well as parent and teacher rating scales. The review concludes that valid assessment of attention and related skills can be effectively achieved in preschool children, with appropriate cautions.     

Screening methods: current status

Two technologies are currently used to screen newborn infants for hearing, auditory brainstem response (ABR), and otoacoustic emissions (OAEs). Each technology is based on detecting the infant's physiologic response to auditory stimulation. ABR is a short-latency auditory evoked response originating from eighth nerve and brainstem auditory pathway structures and detected by scalp surface electrodes. OAEs are auditory signals generated by cochlear outer hair cells in response to acoustic stimulation and detected by a miniature microphone coupled to the infant's ear. Although each technique requires specific sound generation and response recording technologies, advances in computerized stimulus delivery and response detection algorithms allow these tests to be performed by trained technicians or volunteers under the supervision of an audiologist. Results of test performance, and the advantages and disadvantages of each technique are described.     

Psychiatric diagnoses of infants and toddlers referred to a community mental health system

There has been increased interest in improving mental health assessment and treatment of young children. However, there are limited data regarding the prevalence of psychiatric disorders among infants and toddlers. The recent development of measures and classification systems that are specific to this age group has enabled researchers to begin to investigate the social, emotional, and behavioral problems of young children. The present study reviews the major research that has been conducted in this area and examines the prevalence of psychiatric diagnoses of infants and toddlers referred to a public community mental health system. The current investigation also compares the frequency of diagnoses of children who have been evaluated based on the Diagnostic and Statistical Manual (4th edition) with another group of children who were diagnosed based on the Diagnostic Classification: 0-3 system. Although there were some differences between the two samples and classification systems, analysis indicated that parent-child relational problems, adjustment difficulties, regulatory problems, and developmental disorders are some of the more common diagnoses prevalent among young children referred for outpatient treatment. As diagnostic measures and classification systems continue to improve, clinicians will have a better understanding of the mental health problems and treatment needs of young children.     

Hearing-Loss Effects on a Procedural Task Sequence

40 deaf and 40 hearing children representing 2 age groups were blindfolded and presented with 3 high-relief finger mazes of increasing complexity. It was found that young deaf children performed the most difficult task more efficiently than comparable hearing children. Contrary to previous findings, hearing children showed no advantage over deaf children on any of the three tasks as a result of their supposed greater facility with verbal conceptual mediators. The results were interpreted as supporting the idea that deaf children compensate for their auditory lack and verbal deficiency by developing problem solving skills that maximize sensitivity to other sensory modalities.     

Multiple definitions of reading disability: implications for preschool screening

A preschool screening battery was evaluated for effectiveness in identifying children who later would be found to have reading disabilities. The battery was used to evaluate 165 preschool children; 95 of these children were available for 3-yr. follow-up assessment. The battery was effective in identifying children at risk for later reading disability by using four different diagnostic criteria. The data suggest that intervention should be directed toward the immature or young boy who shows weaknesses in the preschool acquisition of number concepts and symbol recognition.     

The impact of aging and hearing status on verbal short-term memory

The aim of this study is to assess the impact of hearing status on age-related decrease in verbal short-term memory (STM) performance. This was done by administering a battery of verbal STM tasks to elderly and young adult participants matched for hearing thresholds, as well as to young normal-hearing control participants. The matching procedure allowed us to assess the importance of hearing loss as an explanatory factor of age-related STM decline. We observed that elderly participants and hearing-matched young participants showed equal levels of performance in all verbal STM tasks, and performed overall lower than the normal-hearing young control participants. This study provides evidence for recent theoretical accounts considering reduced hearing level as an important explanatory factor of poor auditory-verbal STM performance in older adults.     

Communication options for children with hearing loss

This article examines the communication options that are available for use within families of infants and young children who are hard-of-hearing or deaf. The need for language development, regardless of the specific communication mode, is stressed. The demands of the current environment of early identification and intervention often put families in a position of needing to decide among communication methods before they are fully knowledgeable and/or emotionally ready. Specific communication options are delineated and considered within a continuum of spoken and visual language. Available research related to early acquisition of language by infants and young children who are hard-of-hearing and deaf is reviewed; outcomes, when available, are presented for specific methods from reports of older children. Factors that influence families' decisions regarding the selection of a communication option are highlighted in the context of the existing literature. An ongoing evaluative process that respects the choices of families is advocated; a context in which change(s) in communication mode through childhood is viewed as a positive circumstance. The ultimate goal in the selection of any communication approach is to ensure that infants and young children who are hard of hearing or deaf and their families are language proficient and fluent communicators.     

Temperament and adaptation in infants and young children with disabilities

The study of temperament in infants and young children has been facilitated by an increased availability of measures and a growth of interest in individual difference variables. As an index of behavioral style, temperament is well suited to examine individual differences in adaptation of infants and young children to requirements of the caregiving environment. Given the biobehavioral base attributed to temperament, it may have unique significance in understanding the complexities of adaptation of children whose disabilities are often associated with nervous system deficits. Research and clinical studies are reviewed to consider three questions: (1) to what extent do infants and young children with disabilities differ from their nondisabled peers in behavioral style, (2) in what ways may temperament mediate the adaptation of such infants to environmental demands, and (3) what are the implications for clinical practice, interpreted within a goodness-of-fit context.     

Synchrony,complexity and directiveness in mothers’ interactions with infants pre- and post-cochlear implantation

This study investigated effects of profound hearing loss on mother–infant interactions before and after cochlear implantation with a focus on maternal synchrony, complexity, and directiveness. Participants included two groups of mother–infant dyads: 9 dyads of mothers and infants with normal hearing; and 9 dyads of hearing mothers and infants with profound hearing loss. Dyads were observed at two time points: Time 1, scheduled to occur before cochlear implantation for infants with profound hearing loss (mean age = 13.6 months); and Time 2 (mean age = 23.3 months), scheduled to occur approximately six months after cochlear implantation. Hearing infants were age-matched to infants with hearing loss at both time points. Dependent variables included the proportion of maternal utterances that overlapped infant vocalizations, maternal mean length of utterance, infant word use, and combined maternal directives and prohibitions. Results showed mothers’ utterances overlapped the vocalizations of infants with hearing loss more often before cochlear implantation than after, mothers used less complex utterances with infants with cochlear implants compared to hearing peers (Time 2), and mothers of infants with profound hearing loss used frequent directives and prohibitions both before and after cochlear implantation. Together, mothers and infants adapted relatively quickly to infants’ access to cochlear implants, showing improved interactional synchrony, increased infant word use, and levels of maternal language complexity compatible with infants’ word use, all within seven months of cochlear implant activation.     

Infant information processing and family history of specific language impairment: converging evidence for RAP deficits from two paradigms

An infant's ability to process auditory signals presented in rapid succession (i.e. rapid auditory processing abilities [RAP]) has been shown to predict differences in language outcomes in toddlers and preschool children. Early deficits in RAP abilities may serve as a behavioral marker for language-based learning disabilities. The purpose of this study is to determine if performance on infant information processing measures designed to tap RAP and global processing skills differ as a function of family history of specific language impairment (SLI) and/or the particular demand characteristics of the paradigm used. Seventeen 6- to 9-month-old infants from families with a history of specific language impairment (FH+) and 29 control infants (FH-) participated in this study. Infants' performance on two different RAP paradigms (head-turn procedure [HT] and auditory-visual habituation/recognition memory [AVH/RM]) and on a global processing task (visual habituation/recognition memory [VH/RM]) was assessed at 6 and 9 months. Toddler language and cognitive skills were evaluated at 12 and 16 months. A number of significant group differences were seen: FH+ infants showed significantly poorer discrimination of fast rate stimuli on both RAP tasks, took longer to habituate on both habituation/recognition memory measures, and had lower novelty preference scores on the visual habituation/recognition memory task. Infants' performance on the two RAP measures provided independent but converging contributions to outcome. Thus, different mechanisms appear to underlie performance on operantly conditioned tasks as compared to habituation/recognition memory paradigms. Further, infant RAP processing abilities predicted to 12- and 16-month language scores above and beyond family history of SLI. The results of this study provide additional support for the validity of infant RAP abilities as a behavioral marker for later language outcome. Finally, this is the first study to use a battery of infant tasks to demonstrate multi-modal processing deficits in infants at risk for SLI.