Minimal Hearing Loss in Children: The Facts and the ... - PhonakPro

C HAPTER E IGHTEEN Minimal Hearing Loss in Children: The Facts and the Fiction Anne Marie Tharpe

Introduction

Since that time, others have adopted these definitions in an effort to enable meaningful comparisons of data across studies (Centers for Disease Control and Prevention 2005). Our attempts to evaluate current data obtained across studies are compromised when we are not using uniform definitions. For example, prevalence rates of minimal or mild bilateral hearing loss and unilateral hearing loss are uncertain because of the differences in defining the audiometric thresholds of these groups. Furthermore, because we do not currently target minimal and mild degrees of hearing loss with our newborn hearing screening programs, we can only estimate prevalence of such losses in the newborn period. Johnson and colleagues (2005) offered a conservative estimate of 0.55/1000 newborns with mild permanent bilateral (25–40 dB at 1.0, 2.0, or 4.0 kHz) and unilateral hearing loss. The number of babies with unilateral hearing loss in the neonatal period has been estimated at 0.7–1/1000 (Prieve et al. 2000; Davis, DeVoe and Robertson 2005) as compared to 3/100 by school age (Bess et al. 1998). Bess and colleagues also estimated 2.4/100 school-age children had minimal bilateral hearing loss. The difference between estimated prevalence rates in the newborn period and at school age can be the result of several different factors including: • misses by the early hearing detection and intervention systems (EHDI); • low follow-up rates by newborn screening programs resulting in low estimates in the newborn period; • progressive or late-onset hearing loss; and/or • differing definitions of “hearing loss”. This chapter will review what we know about the impact of minimal degrees of hearing loss on children. Perhaps more importantly, what we do not know about the effects of these degrees of hearing loss will also be discussed.

Children with minimal degrees of hearing loss have been of interest to audiologists for decades, but particularly since the 1980s. Some of the most extensive studies of that time were conducted under the direction of Bess (1986). It was at that time that the impact of minimal hearing loss on child development was realized, and policy changes began to be implemented in an attempt to improve outcomes. A starting point in our discussion of this topic should reasonably be the definition of what is meant by minimal hearing loss. However, even the term “minimal” is controversial as it might imply that these losses are not important or are inconsequential. Furthermore, it is common for varying degrees and configurations of hearing loss to fall into the general category of “minimal”. In 1998, Bess, Dodd-Murphy and Parker defined minimal hearing loss as • unilateral sensorineural hearing loss – average air-conduction thresholds (.5, 1.0, 2.0 kHz) > 20 dB HL in the impaired ear and an average air-bone gap no greater than 10 dB at 1.0, 2.0, and 4.0 kHz and average air-conduction thresholds in the normal hearing ear < 15 dB HL; • bilateral sensorineural hearing loss – average puretone thresholds between 20 and 40 dB HL bilaterally with average air-bone gaps no greater than 10 dB at frequencies 1.0, 2.0, and 4.0 kHz; • high-frequency sensorineural hearing loss – air-conduction thresholds greater than 25 dB HL at two or more frequencies above 2 kHz (i.e., 3.0, 4.0, 6.0, or 8.0 kHz) in one or both ears with air-bone gaps at 3.0 and 4.0 kHz no greater than 10 dB. Address correspondence to: Anne Marie Tharpe, Ph.D., Professor, Vanderbilt Bill Wilkerson Center, 1215 21st Ave. So., #8310, Medical Center East, So. Tower, Nashville, TN. 37232-8242, [email protected].

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A Sound Foundation Through Early Amplification

What We Know In the 1980s, Bess and colleagues published a series of papers on the impact of permanent unilateral hearing loss (UHL) on speech-language, auditory, and psychoeducational outcomes in children (Bess and Tharpe 1986; Bess, Tharpe and Gibler 1986; Culbertson and Gilbert 1986; Klee and Davis-Dansky 1986). Prior to that time, most hearing professionals assumed that children with UHL would experience little if any adverse effects as long as they received preferential classroom seating. However, the results of those studies changed our thinking about how children with UHL should be managed. Perhaps the most surprising finding from those studies was that children with UHL were at academic and psychosocial risk. In fact, approximately 35% of these children had to repeat at least one grade in school and an additional 13% required resource assistance for academic difficulty. The academic failure rate was ten times that of their normal-hearing peers, a finding that was upheld by others (Oyler, Oyler and Matkin 1988). More recent reviews of the literature have confirmed that the academic difficulties experienced by children with UHL in early studies have not, on average, improved over time (Watier-Launey, Soin, Manceau and Ployet 1998; English and Church 1999; Lieu 2004). The revelation of these findings was followed by a number of studies that were initiated to examine more closely the potential causative factors (e.g., speech-language, auditory, cognitive abilities) for these academic difficulties. Children with right ear impairment were found to be at greater academic risk than those with left ear impairment (Bess et al. 1986; Oyler et al. 1988; Jensen, Børre and Johansen 1989) and those with more severe degrees of unilateral loss were often found to be at greater risk than those with lesser degrees of loss (Bess and Tharpe 1986; Brookhauser, Worthington, and Kelly 1991; Sedey, Stredler-Brown and Carpenter 2005) but not always (Dancer, Burl and Waters 1995). Although all children enrolled in the Bess et al. studies had intelligence quotients (IQs) that were within normal limits, those who required grade repetition in school had significantly lower verbal IQs than those who were academically successful. But, surprisingly, speech and language evaluations did not reveal differences between those school-age children with UHL and their normal hearing peers (Klee and Davis-Dansky 1986). Other studies have also failed to find speech-language deficits in children with UHL (Hallmo, Møller, Lind and Tonning 1986; Tieri, Masi, Ducci and Marsella

1988; Kiese-Himmel 2002), but at least one study of preschool-age children identified specific language deficits (Sedey et al. 2005). Approximately a decade following the publication of the landmark Bess studies on children with UHL, Bess and colleagues broadened their investigation to include children with permanent, minimal bilateral hearing loss (MBHL; Bess et al. 1998). The psychoeducational findings from that study were remarkably similar to those from the study of children with UHL. That is, the expanded group of school-age children with MBHL and UHL, on average, had an academic failure rate of approximately 37% with an additional 8% requiring resource assistance. The Comprehensive Test of Basic Skills revealed that these children, at the third grade level, had significantly lower scores than their normalhearing peers on sub-tests of reading, language mechanics, word analysis, spelling and science. Similarly, a report from the Third National Health and Nutrition Examination Survey (NHANES-III) revealed that children aged 6–16 years with UHL or MBHL were twice as likely to score two standard deviations below the norm on standardized math and reading tests than normal hearing children(Ross, Visser, Holstrum and Kenneson 2005). Most studies that examined speech and language abilities of children with MBHL included them as part of a larger group of children with greater degrees of loss. For example, Blair and colleagues (Blair, Peterson and Viehweg 1985) compared a group of children with mild bilateral hearing loss (25–45 dB in the better ear) with their normal hearing peers. They found that the vocabulary, reading, comprehension and language use of the children with mild hearing loss was lagging behind that of their normal hearing peers. Likewise, Davis, Elfenbein, Schum and Bentler (1986) found that children with mild bilateral hearing loss (< 45 dB PTA) had receptive vocabulary, verbal ability and reasoning scores that were more than one standard deviation below the mean. In addition, numerous investigators have reported behavior problems in children with UHL relative to children with normal hearing (Keller and Bundy 1980; Stein 1983; Bess et al. 1986; Oyler et al. 1988; Brookhouser et al. 1991; Dancer et al. 1995; English and Church 1999), although this has not been a universal finding (Colleti, Fiorino, Carner and Rizzi 1988). In addition to traditional psychoeducational and speech-language evaluations, Bess and colleagues utilized functional health status assessments, the Cooperative Information Project Adolescent Chart Method (COOP; Nelson et al. 1987; Nelson, Wasson, Johnson

Minimal Hearing Loss in Children: The Facts and the Fiction

and Hays 1996). These charts were designed to assess the domains of physical, emotional, and social functionality. The COOP scores revealed that school-age children with MBHL and UHL had self-perceived deficits in the areas of energy, stress, social support, self-esteem and behavior (Bess et al. 1998). The findings from the COOP evaluations led to an interest in examining listening effort and fatigue in children with minimal to moderate degrees of bilateral hearing loss. Listening effort refers to the attentional requirements necessary to understand speech (Downs 1982; Feuerstein 1988) and fatigue refers to the weariness that results from exertion, either physical or mental. When considering children with hearing loss, we are interested in the potential for mental fatigue that relates to one’s ability to attend or concentrate and contributes to a general feeling of being tired (Grandjean 1979; Kennedy 1988). Bourland-Hicks and Tharpe (2002) utilized salivary-cortisol measures to examine fatigue and a dual-task paradigm (visual attention and listening-innoise tasks) to examine listening effort. Neither cortisol measurements nor self-rated measures of fatigue revealed significant differences between children with minimal to moderate degrees of hearing loss and their normal-hearing peers. However, the dual-task paradigm utilized to study listening effort indicated that children with hearing loss in this study expended more effort in listening than children with normal hearing. In dualtask paradigms, a decrease in performance on the secondary task has been related to the amount of effort expended in performing the primary task (Broadbent 1958). The primary task in this paradigm was a speech recognition measure in quiet and noise conditions (+10, +15, +20 dB), while the secondary task was a visual attention measure requiring the children to push a button whenever a small light-emitting diode (LED) was activated. Reaction times in pushing the button for the activated LED were significantly slower in all conditions for the children with hearing loss relative to the children with normal hearing. Therefore, the children with hearing loss were presumed to be expending more effort in performing the word repetition task than their normal hearing peers. The authors concluded that it is reasonable to expect students with minimal to moderate degrees of hearing loss will have similar expenditures of listening effort in the “real world” as those children under experimental conditions. That is, children are asked to perform multiple tasks in the classroom while listening to their teacher – tasks that can include note taking, answering questions, and/or following directions. There-

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fore, it is likely that secondary task performance (e.g., following directions, taking notes, etc.) might be compromised.

What We Don’t Know Despite the fact that audiologists and educators are better informed about the potential impact of MBHL and UHL on children today than they were in the 1980s (Reeve, Davis and Hind 2001; McKay 2002), it does not appear that the psychoeducational outcomes for these children are, on average, any brighter (Dancer et al. 1995; English and Church 1999). That is, even though more children with MBHL and UHL appear to be receiving audiological and related services than ever before, academic difficulties persist in this group. Therefore, it has been speculated that other factors in addition to hearing loss alone may be at play. Keeping in mind that the majority of children with MBHL and UHL demonstrate no academic, speech, language or behavior problems, there must exist some contributing or predictive factors not yet identified that affect those children who do not fare as well. For example, the etiology of the hearing loss, rather than the hearing loss itself, might be an indicator of potential deficits. Consider that approximately 10,000 to 80,000 infants are born in the United States each year with congenital cytomegalovirus (CMV) infection (Stagno et al. 1986; Noyola, Demmler and Nelson 2001) making CMV the most common congenital viral infection and the leading cause of prelinguistic hearing loss in children (Nance 2007). Nance posited that the neurologic deficits associated with CMV might be to blame for the poor academic performance of children with UHL secondary to infection, rather than the hearing loss per se. At this time, we have not been able to make a convincing link between the academic difficulties of children with MBHL or UHL and CMV, or any other causative factor. However, should this speculation hold true, there is the implication that intervention strategies would need to encompass more than improvement of classroom acoustics or speech perception and that specific educational and speech/language interventions would also need to be explored. Another possible contributing factor to the academic difficulties experienced by these children could be their late age of identification and/or intervention. Although hearing loss of moderate or greater degree can be identified in the newborn period, universal newborn screening protocols do not target hearing loss in the minimal to mild range (Joint Committee on Infant Hear-

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ing 2007) and evidence exists to suggest that a large percentage of newborns with these losses are missed during the screening process (Johnson et al. 2005). Furthermore, with no mandated hearing screening prior to school entrance, children with minimal to mild degrees of hearing loss are not likely to be identified until approximately five to six years of age. Another potential contributor to late intervention for these children is that many families, physicians, and audiologists are either not concerned about such losses or are understandably uncertain as to appropriate management for these children (Neault 2005a). Hence, these children, even once identified, may not receive timely intervention (Reeve 2005; McKay, Gravel and Tharpe 2008). At the National Workshop for Mild and Unilateral Hearing Loss held in 2005, discussions ensued regarding when minimal to mild hearing loss could be accurately diagnosed in infants (Cone-Wesson, Sininger and Widen 2005). Using the definitions of slight hearing loss (16–25 dB HL) and mild hearing loss (26–40 dB HL), it was concluded that, under ideal conditions, slight loss could be identified between 6 and 9 months developmental age and mild loss at 6 months or younger developmental age. Factors that make identification at such an early age difficult include the presence of otitis media with effusion, calibration issues and lack of agreement between physiologic and behavioral test measures (Ross et al. 2008), and examiner uncertainty (Reeve 2005). One of the most common audiologic interventions for minimal bilateral and unilateral hearing loss, frequency-modulated (FM) system technology, enhances speech perception under adverse listening conditions (Kenworthy, Klee and Tharpe 1990; Updike 1994; Flexer 1995; Tharpe, Ricketts and Sladen 2003). Various types of hearing aids have also been recommended for those with MBHL and UHL (McKay et al. 2008). However, as noted previously, there is no direct evidence that improving listening via hearing aids or FM usage for children with MBHL and UHL improves academic outcomes for these children, although one would expect that to be the case.

Conclusions Although we know that more than a third of children with MBHL or UHL will experience academic difficulty, at this point in time, we do not know which children will be negatively affected or which interventions might be effective. Until such time that those children who are at greatest risk for psychoeductional difficulty

can be identified, it is reasonable to institute a proactive management approach with children who have MBHL or UHL. This approach includes: • Counseling. Audiologists can counsel families about the importance of a good acoustic environment for communication and how to create a rich language atmosphere within the home. For those with UHL, a discussion regarding safety issues related to poor localization skills should also be included. When appropriate, these discussions can include daycare professionals and schoolteachers. Keeping in mind that the effects of these losses will likely be subtle, parents might not understand that their child with MBHL or UHL hears any differently than other children. Therefore, our counseling challenge is to explain or demonstrate to families, perhaps through the use of simulations or other tools, the impact these losses may have on listening, as they may not be readily apparent. • Etiologic Evaluation. Medical evaluation of children found with any degree or configuration of permanent hearing loss should include a search for genetic and environmental causes. As previously noted, CMV is the most common causative factor of non-genetic, prelingual hearing loss and must be identified during the first two to three weeks of life. Other causative factors associated with MBHL and UHL include prematurity, genetics, enlarged vestibular aquaduct (EVA), noise exposure, viral and bacterial infections, and auditory neuropathy/dyssynchrony (Tharpe and Sladen 2008). • Acoustic Modifications. Preferential seating arrangements may help to provide children with MBHL and UHL with enhanced visual and auditory cues needed for improved communication. Modifications may be needed in the home, daycare setting, and/or school environment. These modifications can be inexpensive and low-tech, like strategic placement of carpet remnants within the room, or might be high-tech, like the placement of a sound field FM system. • Speech and Language Monitoring. Although most studies of speech and language abilities of school-age children with UHL have not identified specific deficits (Hallmo et al. 1986; Klee and Davis-Dansky 1986; Tieri et al. 1988; Kiese-Himmel 2002), at least one study found that children with UHL who failed a grade in school had significantly lower verbal IQ scores than those children with UHL who were academically successful (Klee and Davis-Dansky 1986). However, both the academically successful and unsuccessful UHL groups had verbal IQs within the normal range. Examination of the speech and language abilities of chil-


dren with MBHL has been lacking. Despite the fact that no clear pattern of speech and/or language deficits has emerged in children with MBHL or UHL, obtaining a speech and language evaluation provides a good opportunity to document baseline functioning and allows a speech-language pathologist to talk with families about how to support a language-rich home environment. • Ongoing Audiologic Assessment. As with any degree of hearing loss, audiological monitoring is important for identification of progression or fluctuation. Many of the causative factors of minimal hearing loss, including CMV and EVA, are associated with progression. It is also interesting to note that reports are beginning to emerge of babies who failed newborn screening in one ear but were later found to have bilateral hearing loss. Neault recently reported an analysis of two years of newborn hearing screening data from Massachusetts (2005b). Of the babies who did not pass the newborn screening in one ear and had confirmed hearing loss, 40% were later found to have bilateral hearing loss. These babies could have had bilateral loss at the time of the screening but were missed because of screening variables including calibration issues, or the loss could have progressed from unilateral to bilateral between the time of the screening and the diagnostic evaluation. Regardless of the reason for a change from a unilateral to a bilateral hearing loss diagnosis, these data support the need for close audiologic monitoring of UHL. • Functional Auditory Assessments. Another source of information important to the management of MBHL and UHL is functional auditory assessment. Because the behavioral effects of such losses are often more subtle than those of greater degrees of loss, parents, educators, and other professionals may tend to overlook them and think that no problems exist. Functional auditory assessments are designed to evaluate listening behavior in real-world settings, where parents, teachers, and other caregivers spend their time with children. Tools like the Children’s Home Inventory for Listening Difficulties (CHILD; Anderson and Smaldino 2000), for use by parents, or the Screening Inventory for Targeting Educational Risk (SIFTER; Anderson 1989), for use by teachers, can provide valuable information for assisting professionals in developing management plans for children with MBHL and UHL. For example, such tools may reveal that although a child is progressing well academically, there may be difficulty hearing under specific listening conditions (e.g., soft

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speech or speech in noise). Therefore, the results of functional assessment tools, in addition to other evaluations, may support the need for FM system technology or hearing aids (McKay et al. 2008). Many of the functional auditory assessment tools do not have published psychometric data at this time. Therefore, they should be considered as only one part of an assessment battery contributing to management decision making. Children with MBHL and UHL are clearly at risk for academic difficulty. But it is important to keep in mind that not all of these children have difficulty and, at this time, we cannot predict with certainty which children will fare better than others. Furthermore, we do not have strong evidence to support specific intervention strategies, including amplification, for all children with MBHL and UHL (CDC 2005; McKay et al. 2008). Therefore, it is reasonable to monitor the auditory, speech-language, and psychoeducational progress of all children with MBHL and UHL and determine intervention strategies on an individual basis, as needed.

References Anderson, K.L., and Smaldino, J.J. 2000. Children’s Home Inventory for Listening Difficulties (CHILD). Educational Audiology Review 17(3) Suppl. Retrieved February 11, 2008, from www.hear2learn.com. Anderson, K.L. 1989. Screening Instrument for Targeting Educational Risk (SIFTER). Retrieved February 11, 2008, from www.hear2learn.com. Bess, F.H. 1986. Unilateral hearing loss in children. Ear and Hearing 7(1). Bess, F.H., and Tharpe, A.M. 1986. Case history data on unilaterally hearing-impaired children. Ear and Hearing 7:14–19. Bess, F.H., Tharpe, A.M., and Gibler, A.M. 1986. Auditory performance of children with unilateral hearing loss. Ear and Hearing 7: 20–26. Bess, F.H., Dodd-Murphy, J.D., and Parker, R.A. 1998. Children with minimal sensorineural hearing loss: Prevalence, educational performance, and functional health status. Ear and Hearing 17: 1–11. Blair, J.C., Peterson, M.E., and Viehweg, S.H. 1985. The effects of mild sensorineural hearing loss on academic performance of young school-age children. Volta Review 87: 87–93. Bourland-Hicks, C., and Tharpe, A.M. 2002. Listening effort and fatigue in school-age children with and without hearing loss. Journal of Speech, Hearing and Language Research 45: 573–584.

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Broadbent, D.E. 1958. Perception and Communication. New York: Pergamon Press. Brookhauser, P.E., Worthington, D.W., and Kelly, W.J. 1991. Unilateral hearing loss in children. Laryngoscope 101 (12, pt 1): 1264–1272. Centers for Disease Control and Prevention 2005. National workshop on mild and unilateral hearing loss: Workshop proceedings. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Colletti, V., Fiorino, F.G., Carner, M., and Rizzi, R. 1988. Investigation of the long-term effects of unilateral hearing loss in adults. British Journal of Audiology 22: 113–118. Cone-Wesson, B., Sininger, Y., and Widen, J. 2005. Issues associated with conducting diagnostic audiologic evaluations in children with suspected mild and unilateral hearing loss. National workshop on mild and unilateral hearing loss: Workshop proceedings. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Culbertson, J.L., and Gilbert, L.E. 1986. Children with unilateral sensorineural hearing loss. Ear and Hearing 7(1): 38–42. Dancer, J., Burl, N.T., and Waters, S. 1995. Effects of unilateral hearing loss on teacher responses to the SIFTER: Screening Instrument for Targeting Educational Risk. American Annals of the Deaf 140: 291–294. Davis, A., DeVoe, S., and Robertson, H. 2005. UK Trial of Early Amplification in Children with Unilateral or Mild Hearing Impairments. Presentation at the National workshop on mild and unilateral hearing loss: Workshop proceedings. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Davis, J., Elfenbein, J., Schum, R., and Bentler, R. 1986. Effects of mild and moderate hearing impairments on language, educational, and psychosocial behavior of children. Journal of Speech and Hearing Disorders 51: 53–62. Downs, D.W. 1982. Effects of hearing aid use on speech discrimination and listening effort. Journal of Speech, Language and Hearing Disorders 47: 189–193. English, K., and Church, G. 1999. Unilateral hearing loss in children: An update for the 1990s. Language, Speech and Hearing Services in the Schools 30: 26–31. Feuerstein, J. F. 1988. Ease of listening, speech discrimination, and attentional effort in binaural and monaural listening by normal-hearing adults. Doctoral dissertation, University of New York at Buffalo, New York. Flexer, C. 1995. Classroom management of children with minimal hearing loss. Hearing Journal 48: 10–13.

Grandjean, E. 1979. Fatigue in industry. British Journal of Industrial Medicine 36:175–186. Hallmo, P., Møller, P., Lind, O., and Tonning, F.M. 1986. Unilateral sensorineural hearing loss in children less than 15 years of age. Scandinavian Audiology 15: 131–137. Jensen, J.H., Børre, S., and Johansen, P.A. 1989. Unilateral sensorineural hearing loss in children: Cognitive abilities with respect to right/left differences. British Journal of Audiology 23:215–220. Johnson, J.L., White, K.R., Widen, J.E., Gravel, J.S., James, M., Kennalley, T., Maxon, A.B., Spivak, L., Sullivan-Mahoney, M., Vohr, B.R., Weirather, Y., and Holstrum, J. 2005. A multicenter evaluation of how many infants with permanent hearing loss pass a two-stage otoacoustic emissions/automated auditory brainstem response newborn hearing screening protocol. Pediatrics 116(3): 663–72. Joint Committee on Infant Hearing 2007. Year 2007 position statement: Principles and guidelines for early hearing detection and intervention programs. Pediatrics 120(4): 898–921. Keller, W.D., and Bundy, R.S. 1980. Affects of unilateral hearing loss upon educational achievement. Child: Care, Health and Development 6: 93–100. Kennedy, H.G. 1988. Fatigue and fatigability. British Journal of Psychiatry 153:1–5. Kenworthy, O.T., Klee, T. and Tharpe, A.M. 1990. Speech recognition ability of children with unilateral sensorineural hearing loss as a function of amplification, speech stimuli and listening condition. Ear and Hearing 11:264–270. Kiese-Himmel, C. 2002. Unilateral sensorineural hearing impairment in childhood: Analysis of 31 consecutive cases. International Journal of Audiology 41:57–63. Klee, T.M., and Davis-Dansky, E. 1986. A comparison of unilaterally hearing-impaired children and normalhearing children on a battery of standardized language tests. Ear and Hearing 7(1): 27–37. Lieu, J.E. 2004. Speech-language and educational consequences of unilateral hearing loss in children. Archives of Otolaryngology, Head and Neck Surgery 130: 524–30. McKay, S. 2002. To aid or not to aid: Children with unilateral hearing loss. Healthy Hearing Accessed online at http://www.healthyhearing.com/library/article_content.asp?article_id=163. McKay, S., Gravel, J.S., and Tharpe, A.M. 2008. Amplification considerations for children with minimal or mild bilateral hearing loss and unilateral hearing loss. Trends in Amplification 12(1): 43–54.


Nance, W. 2007. How can newborn hearing screening be improved? Paper presented at AudiologyNOW, Denver, Colorado. Nelson, E.C., Wasson, J., Kirk, J., Keller, A., Clark, D., Dietrich, A., Stewart, A., and Zubkoff, M. 1987. Assessment of function in routine clinical practice: Description of the COOP chart method and preliminary findings. Journal of Chronic Disease 40 (Suppl 1): 555–635. Nelson, E.C., Wasson, J.H., Johnson, D., and Hays, R. 1996. Dartmouth COOP functional health assessment charts: Brief measures for clinical practice. In B. Spilker (ed.), Quality of Life and Pharmacoeconomics in Clinical Trials 2nd ed. (pp.161–168). Philadelphia: Lippencott-Raven Publishers. Neault, M. 2005a. Differences in outcomes for right ear vs. left ear unilateral hearing losses. In: National Workshop on Mild and Unilateral Hearing Loss: Workshop Proceedings. Breckenridge, CO: Centers for Disease Control and Prevention. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Neault, M. 2005b. Progression from unilateral to bilateral loss. In: National Workshop on Mild and Unilateral Hearing Loss: Workshop Proceedings. Breckenridge, CO: Centers for Disease Control and Prevention. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Noyola, D., Demmler, G., and Nelson, C. 2001. Early predictors of neurodevelopmental outcome in symptomatic congenital cytomegalovirus infection. Journal of Pediatrics 128:325–331. Oyler, R., Oyler, A. and Matkin, N. 1988. Unilateral hearing loss: Demographics and educational impact. Language, Speech and Hearing Services in Schools 19: 191–210. Prieve, B., Dalzell, L., Berg, A., Bradley, M., Cacace, A., Campbell, D., DeCristofaro, J., Gravel, J., Greenberg, E., Gross, S., Orlando, M., Pinheiro, J., Regan, J., Spivak, L., and Stevens, F. 2000. The New York State universal newborn hearing screening demonstration project: Outpatient outcome measures. Ear and Hearing 21(2): 104–117. Reeve, K. 2005. Audiological management and family factors for children with mild and unilateral hearing impairment. Presented at the National Workshop on Mild and Unilateral Hearing Loss: Workshop proceedings. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Reeve, K., Davis, A.C., and Hind, S. 2001. Mild and unilateral hearing impairments: What the clinicians think. Poster presentation at A Sound Foundation Through Early Amplification Conference, Chicago.

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Ross, D.S., Holstrum, W.J., Gaffney, M., Green, D., Oyler, R.F., and Gravel, J.S. 2008. Hearing screening and diagnostic evaluation of children with unilateral and mild bilateral hearing loss. Trends in Amplification 12: 27–34. Ross, D.S., Visser, S., Holstrum, J., and Kenneson, A. 2005. Minimal hearing loss and cognitive performance in children: Brief Update. Presented at the National Workshop on Mild and Unilateral Hearing Loss: Workshop proceedings. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Sedey, A., Stredler-Brown, A., and Carpenter, M.A. 2005. Language outcomes in young children with unilateral hearing loss. Presentation at the National Workshop on Mild and Unilateral Hearing Loss: Workshop proceedings. Retrieved January 14, 2008 from www.cdc.gov/ncbddd/ehdi. Stagno, S., Pass, R.F., Cloud, G., Britt, W.J., Henderson, R.E., Walton, P.D., Veren, D.A., Page, F., and Alford, C.A. 1986. Primary cytomegalovirus infection in pregnancy: Incidence, transmission to fetus, and clinical outcome. Journal of the American Medical Association 256(14). Stein, D. 1983. Psychosocial characteristics of schoolage children with unilateral hearing losses. Journal of the Academy of Rehabilitative Audiology 16:12–22. Tharpe, A.M., Ricketts, T., and Sladen, D.P. 2003. FM systems for children with minimal to mild hearing loss. Proceedings from the 1st International FM Conference. In D. Fabry and C.D. Johnson (eds.), ACCESS: Achieving Clear Communication Employing Sound Solutions (pp. 191–197). Warrenville, IL: Phonak AG. Tharpe, A.M. and Sladen, D.P. 2008. Causation of permanent unilateral and mild bilateral hearing loss in children. Trends in Amplification 12: 17–25. Tieri, L., Masi, R., Ducci, M., and Marsella, P. 1988. Unilateral sensorineural hearing loss in children. Scandinavian Audiology (suppl.) 30:33–36. Updike, C.D. 1994. Comparison of FM auditory trainers, CROS aids and personal amplification in unilaterally hearing impaired children. Journal of the American Academy of Audiology 5: 204–209. Watier-Launey, C., Soin, C., Manceau, A. and Ployet, M.J. 1998. Necessity of auditory and academic supervision in patients with unilateral hearing disorder: Retrospective study of 175 children. Annals of Otolaryngology 115: 149–55.