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.

Practical considerations of real-ear-to-coupler difference measures in infants.

The purpose of this study was to investigate some of the practical issues surrounding the use of the real-ear-to-coupler difference (RECD) measure in infants in clinical settings. Twenty-two newborns were seen once a month during their first year of life for the purpose of obtaining RECD measurements. Two methods for obtaining the RECD were examined: the commonly used constant insertion depth method and the acoustic method. Differences between the results of the two methods were examined as well as test-retest reliability for each. Findings suggest that no compelling evidence exists to support the use of one of these methods over the other. Use of either method resulted in good test-retest reliability in the midfrequency range of the RECD, with poorer reliability on both ends of the frequency spectrum. Test-retest reliability decreased with increasing age for both methods. In addition, reliability of between-ear RECD values was examined. Between-ear measurements were most reliable in the midfrequency range, and reliability decreased slightly with increasing age.

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.

Behavioral auditory assessment of young infants: methodological limitations or natural lack of auditory responsiveness?

The determination of auditory thresholds by means of behavioral techniques in young infants can be difficult. This could be the result of limitations in methodology, a lack of observable auditory responsiveness, or both. In the current study, 2- and 4-month old infants were tested under enhanced conditions for obtaining behavioral responses (i.e., salient auditory stimuli, reduced visual distractions, reinforced correct responses). A two-interval, forced-choice task with four intensity levels was used. Although a behavioral threshold was obtained for the 4-month-olds, threshold determination for the 2-month-olds remained elusive. In light of the current findings and previous studies of visual acuity of infants, these results suggest a lack of behavioral responsiveness to auditory stimuli for the younger infants rather than methodological limitations. With infants in the 2-month-old age range, clinical audiologists should expect few behavioral responses to auditory stimuli at intensity levels below those that elicit startle responses.

Minimal, progressive, and fluctuating hearing losses in children. Characteristics, identification, and management.

Referring to specific types of hearing loss as "minimal" or "mild" seems to imply that their effects are equally mild or negligible. A growing body of literature, however, supports the notion that such losses can have a significant impact on the communicative and educational development of young children. Although OME is considered a common childhood ailment, mounting evidence suggests that it is not always benign and may contribute to significant educational and communicative difficulties in some young children when accompanied by conductive hearing loss. Even very mild bilateral and unilateral SNHL seems to contribute to problems in the areas of social and emotional function, educational achievement, and communication in some children. Because these hearing losses are so mild, they may not be immediately recognized as the source of such difficulties. The purpose of this report is to heighten the general pediatrician's awareness of the significance of even very mild or minimal hearing losses in children. As the gatekeepers for children's health care, pediatricians are typically the primary recipients of parental expressions of concern and the initiators of evaluations or referrals to address such.

Landau-Kleffner syndrome: acquired epileptic aphasia in children.

Acquired epileptic aphasia, or Landau-Kleffner syndrome (LKS), once thought to be a rare syndrome, may occur more frequently in the pediatric population than once thought. This syndrome is typically characterized by an abrupt or gradual loss of language ability and inattentiveness to sound, sometimes called auditory agnosia, with onset during the first 5 years of life. This interruption in communication ability is generally closely preceded, accompanied, or followed by the onset of seizure activity and/or abnormal electro-encephalographic (EEG) findings. This report describes two cases of LKS evaluated at the same hearing and speech center. Because of the characteristic language regression and inattentiveness to sound, speech-language pathologists and audiologists are likely to be among the first professionals to evaluate these children. It is imperative that communication specialists be alert to the characteristic symptoms of LKS in order to be instrumental in initiating an appropriate diagnostic and management process. A multidisciplinary approach to identification and rehabilitation is encouraged in order to effectively re-establish communication skills for these children.

Development of an expert system for pediatric auditory brainstem response interpretation.

Expert systems are computer programs which incorporate artificial intelligence technology and are created to emulate the decision-making abilities of human experts. The advantage of such systems lies in their ability to capture and model expert problem solving knowledge in a domain and make it available to an unlimited number of consumers in an economic and efficient way. The purpose of this project was to develop an expert system to interpret infant auditory brainstem response data as entered by the user. The resulting system provides diagnostic conclusions regarding hearing status, type of hearing loss, and brainstem function at an accuracy level equal to that of a human expert.

Computer simulation technique for assessing pediatric auditory test protocols.

Adaptive testing procedures are widely used for evaluating the hearing of young children. A standard protocol for such testing, however, has not been recommended and, as a result, many variations of the procedure are used clinically. This study, by utilizing computer simulations, varied several test parameters and examined the resulting test outcomes. We evaluated the effects of starting level, stimulus step size, and the use of conditioning trials on test outcome, while also varying the hearing levels and false positive and and negative rates of our simulated subjects. Results indicated that a low starting level, with a 20-dB down 10-dB up step size, and no conditioning trials produced the most accurate estimates of thresholds under most conditions.

Diagnostic and management considerations of acquired epileptic aphasia or Landau-Kleffner syndrome.

A small number of children have been identified as having an interruption in their communicative progress known as Landau-Kleffner syndrome, acquired epileptic aphasia, or aphasia with convulsive disorder. Although presenting symptoms have differed among the cases reported, a progressive or acute language loss and inattentiveness to auditory stimuli are the most common manifestations. Typically, these children begin developing language normally and then, for no apparent reason, language progress is disrupted. This disruption is accompanied by the onset of seizure activity and/or abnormal electroencephalographic (EEG) findings. While this disorder appears to be relatively uncommon, its frequency is questionable due to its unfamiliarity among the audiology and otology communities and, thus, it is subject to the likelihood of misdiagnosis. A case of acquired epileptic aphasia is described herein. A team diagnostic and management approach, which can include audiology, otology, psychology, neurology, and speech-language pathology is recommended for such cases. Earlier identification of this debilitating disorder is needed in order to secure appropriate intervention and reestablish communication systems for these children.

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.

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.

Performance and management of children with unilateral sensorineural hearing loss.

This paper reviews the status of children with unilateral sensorineural hearing loss. There is mounting evidence to show that some unilaterally hearing-impaired children experience difficulty in school. Furthermore, these children may have trouble understanding speech in noise, exhibit poor localization skills, and display behavior problems in school and at home. Suggested management strategies for this population are discussed.

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 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.

Unilateral hearing impairment in children.

An overview and update are offered on difficulties experienced by children with monaural sensorineural deafness. It is the general consensus that children with unilateral hearing loss experience few, if any, communication and/or educational problems. The medical and educational status of a group (N = 60) of children with unilateral, hearing impairment are described. In addition, the auditory, linguistic, and behavioral manifestations of unilateral hearing impairment were studied in considerable detail for a subsample of these 60 children. The results revealed that approximately one third of the children with unilateral hearing loss had failed at least one grade. Nearly 50% of the group had either failed a grade and/or needed resource assistance in the schools. The small subsample of children with unilateral hearing loss performed much poorer than a matched group of children with normal hearing on both a localization and a syllable recognition task. Finally, the data on behavioral and linguistic manifestations of monaural hearing loss indicate that children with unilateral hearing impairment are experiencing more problems than previously supposed.

Validity of hearing thresholds obtained from the rising portion of the audiogram in sensorineural hearing loss.

Two experiments were performed for this study. The purpose of both experiments was to examine the validity of pure-tone hearing thresholds obtained near the rising portion of a sensorineural hearing loss. Recent work by other investigators has suggested that thresholds obtained near the rising portion of the audiogram may not correspond to the severity of damage at the cochlear place associated with the test frequency. In the first experiment this issue was addressed in 11 subjects having low-frequency sensorineural hearing loss, whereas 12 subjects (19 ears) having notch-shaped high-frequency sensorineural hearing losses were examined in the second experiment. The results indicated that thresholds obtained from the rising portion of the audiometric configuration were, in most instances, determined by sensitivity at test frequency. An exception to this generalization involved low-frequency sensorineural hearing loss with a slope for the rising portion of the audiogram exceeding -25 dB/octave. In these cases the severity of the loss may be underestimated for test frequencies immediately adjacent to the rising portion of the audiogram.