Anne Marie Tharpe

Auditory performance of children with unilateral sensorineural hearing loss.

Horizontal sound localization and syllable recognition skills were examined in a group of children with unilateral sensorineural hearing loss and a matched group of normal hearers. The results showed that the unilaterally hearing-impaired children performed more poorly than the normal counterparts in both localization and speech recognition of nonsense syllables. The unilaterally hearing-impaired children had considerable difficulty understanding in a background of noise. The clinical implications of these findings are discussed.

Case History Data on Unilaterally Hearing-impaired Children

This paper presents the data from medical and educational case histories on a group of 60 unilaterally hearing-impaired children. The case history data revealed that approximately one-half of the 60 children with unilateral sensorineural hearing loss exhibited some difficulty in educational progress. More specifically, 35% had failed at least one grade and an additional 13% were in need of some special resource assistance. Similar findings were obtained on a subset of 25 unilaterally hearing-impaired children who satisfied rather stringent criteria for age, hearing level, intelligence, length of time the impairment was present, history of middle ear disease, and general growth and development.

Amplification Considerations for Children With Minimal or Mild Bilateral Hearing Loss and Unilateral Hearing Loss

Children with minimal or mild bilateral hearing loss and unilateral hearing loss are at higher risk for academic, speech-language, and social-emotional difficulties than their normal hearing peers. The choice to fit infants with moderate or greater degrees of bilateral hearing loss has been standard practice for most clinicians, but for those with minimal or mild bilateral hearing loss or unilateral hearing loss, the fitting of hearing technology must be based on limited data. Evidence does not yet exist to support all the management decisions that an audiologist must make upon identifying an infant with minimal or mild bilateral hearing loss or unilateral hearing loss. It is not yet known which children are at the greatest risk for educational problems nor is it known if the provision of early amplification in this population will help a child avoid later difficulties. Some of these considerations and current hearing technology options for children with minimal or mild bilateral hearing loss or unilateral hearing loss are reviewed in this article.

An Introduction to Unilateral Sensorineural Hearing Loss in Children

This paper offers a general review of literature on issues pertinent to unilateral hearing loss in children. The paper focuses on such areas as demographic considerations, the importance of binaural hearing, the effects of noise on speech recognition, learning and educational factors, and auditory deprivation. It is concluded that there is sufficient evidence to suspect that children with unilateral sensorineural hearing loss can experience complications in communication and education. Finally, this paper presents the description of a research plan used in our study on unilateral sensorineural hearing loss in children.

Auditory characteristics of children with autism

Objectives: The objectives of this study were (1) to describe the auditory characteristics of children with autism relative to those of typically developing children and (2) to describe the test-retest reliability of behavioral auditory test measures with this population of children with autism. Design: Audiometric data were obtained from 22 children diagnosed with autism and 22 of their typically developing peers. The audiologic test battery consisted of behavioral measures (i.e., visual reinforcement audiometry, tangible reinforcement operant conditioning audiometry, and conditioned play audiometry) and physiological measures (auditory brain stem response audiometry, distortion product otoacoustic emissions, and acoustic reflexes). Results: Children with autism had physiologic test results equivalent to their typically developing counterparts. That is, no differences in auditory brain stem response audiometry, distortion product otoacoustic emissions, or acoustic reflex results were noted between the children with autism and typically developing children. However, behavioral measures revealed that about half of the children diagnosed with autism presented pure-tone averages outside of normal limits (i.e., >20 dB HL), although their response thresholds to speech were within normal limits. All behavioral test results were within normal limits (i.e., ≤20 dB HL) for the typically developing children. In addition, test-retest variability was typically 15 dB or greater for children with autism as compared with variability of 10 dB or less for most of the typically developing children. Conclusions: Children with autism demonstrated essentially equivalent results on a battery of physiological auditory tests as those obtained from typically developing children. However, on average, behavioral responses of children with autism were elevated and less reliable relative to those of typically developing children. Furthermore, approximately half of the children with autism demonstrated behavioral pure-tone averages outside of the normal hearing range (i.e., >20 dB HL) despite having normal to near-normal hearing sensitivity as determined by other audiometric measures.

Speech recognition ability of children with unilateral sensorineural hearing loss as a function of amplification, speech stimuli and listening condition

The purpose of this investigation was to examine three types of audiological recommendations [unaided, CROS (contralateral routing of signals) and personal FM system] and their impact upon speech recognition ability of children with unilateral sensorineural hearing loss. Each of these recommendations was tested under three listening conditions encountered in a classroom [monaural direct (MD), monaural indirect (MI), midline signal/omnidirectional noise (MS/ON)] with two types of speech materials (Nonsense Syllable Test and an American English adaptation on the Bamford-Kowal-Bench Sentence Lists). These experimental conditions were simulated in a classroom, recorded on audiotape, and played back to subjects under headphones to control such factors as signal-to-noise ratio, earmold fit, and head shadow effects. Six school-age children with unilateral hearing losses between 56 and greater than 120 dB HL (PTA) were evaluated using a repeated measures design. The children experienced the most listening difficulty in the MI condition when they were unaided. The CROS aid improved speech recognition in this condition but degraded speech recognition in the MD condition. The FM system was the only audiological recommendation to produce uniformly high speech recognition scores across all listening conditions with both types of speech materials. Implications for the audiological management of unilaterally hearing-impaired children in the classroom are discussed.

Identification and management of children with minimal hearing loss

Throughout the last two decades, we have witnessed a gradual change in the audiological profile of the hearing-impaired child. The number of children with severe to profound hearing losses seems to be declining, while those with minimal losses seems to be increasing. Such losses include unilateral sensorineural, mild bilateral sensorineural, and bilateral conductive hearing loss. Historically, children with minimal hearing loss have received limited attention from physicians, audiologists, or educators. It has been assumed that minimally hearing-impaired children will exhibit few, if any, handicaps and require no special assistance in the academic setting. Recent evidence challenges that assumption, however, and suggests that, in fact, children with minimal hearing loss can demonstrate significant academic and communicative difficulties. It is recommended that children with minimal hearing impairment be considered at high risk for communication and educational difficulties and that assessments be made early in order to identify problems and implement management programs.

Causation of permanent unilateral and mild bilateral hearing loss in children.

Children with permanent unilateral or mild bilateral hearing loss have been a focus of concern by audiologists, educators, and physicians for at least 2 decades. These children are known to be at risk for psychoeducational difficulties. However, despite this concern, little has been learned about the causative factors of these hearing losses and how those factors might be contributing to child development. This review of known causes of permanent unilateral and mild bilateral hearing loss in children is meant to draw attention to the importance of the search for etiologic factors. That is, the identification of the hearing loss should not signal the end of the diagnostic process but, rather, the beginning of a search for causation. With the combined efforts of audiologists, otolaryngologists, pediatricians, geneticists, and other medical professionals, we may enhance our understanding of the primary causes of unilateral and mild bilateral hearing loss and, perhaps, create links between causative factors and psychosocial and psychoeducational outcomes.

A Longitudinal Investigation of Infant Auditory Sensitivity

The behavioral evaluation of hearing in very young infants has been fraught with procedural and interpretive problems. Despite the introduction of current physiological techniques of estimating hearing sensitivity, such as otoacoustic emissions and auditory brainstem-evoked responses, behavioral hearing assessment of young infants remains of interest to researchers of infant behavior and to clinicians who need to use a battery of tests in their assessment of infant hearing. The objective of this study was to provide the first longitudinal investigation of infant auditory sensitivity, using a new procedure for behavioral testing of neonates and infants. Behavioral responses to speech noise stimuli were obtained monthly from birth to 12 months of age. During each trial, the signal increased from an inaudible level in 2-dB steps until the infant responded. Therefore, a threshold estimate was obtained on each trial, and the average threshold could be computed across trials within a test session. Threshold estimates were in good agreement with previously reported infant behavioral thresholds based on cross-sectional designs. The age-related changes in threshold were fit with exponential functions for individual infants and for the group data. There was good agreement in the shape of these functions across infants, with asymptotic threshold level approached around 6 months of age. Therefore, this longitudinal study confirms that the age trend previously reported from cross-sectional findings is also observed in the development of individual infants.

Survey of Hearing Aid Fitting Practices for Children with Multiple Impairments

The fitting of amplification on young children with multiple impairments in addition to hearing loss is a challenge faced regularly by audiologists. However, very little has been published on this topic in the audiological literature. The purpose of this survey was to document hearing aid fitting practices for this population within the United States. Specifically, audiologists who regularly serve children were asked to complete a series of questions on their educational preparation and their hearing aid selection, fitting, and verification practices for children with multiple impairments. For purposes of this survey, multiple impairments included vision impairment, mental retardation, physical impairment, and autism spectrum disorders. Findings from this survey suggest that children with special needs in addition to hearing loss are typically fit in the same way and with the same type of amplification as those with hearing loss only. In addition, differences were noted in hearing aid selection, fitting, and verification practices across work settings. Future directions and research needs are suggested.