May 11, 2018 - https://journals.lww.com/thehearingjournal by ... a patient a child who had a mild unilateral hear- ... minimal hearing loss in the journal Ear and.
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At one time or another, most of you have had as a patient a child who had a mild unilateral hearing loss, or maybe a bilateral high-frequency hearing loss of 30 dB to 40 dB in the 4000-Hz range. In either case, we typically refer to this type of impairment as a “minimal hearing loss,” and we usually think of minimal as...well, minimal. That is, an impairment that usually has minimal consequences. But what if I told you that one out of every three children who have this degree of hearing loss would fail at least one grade in school? And what if I told you also that these children had significantly more emotional and social problems than their normal-hearing peers? This mild form of hearing impairment doesn’t sound so minimal any more, does it? Last October I read an interesting article on minimal hearing loss in the journal Ear and Hearing by Fred Bess, Jeanne Dodd-Murphy, and Robert Parker. These authors assessed the educational and functional impact of this mild form of hearing loss by studying a large group of grade-school children. Their findings were surprising and significant. Many shared my interest in this article, as it was recently given the Ear and Hearing Editor’s Award for outstanding research in audiology and the hearing sciences. To share the important message of this article with our Page Ten readers, we have recruited the senior author, Dr. Bess, to provide us with a summary of his findings. Fred Bess, PhD is head of the Department of Hearing and Speech Sciences, Vanderbilt Bill Wilkerson Center of Otolaryngology and Communication Sciences, Vanderbilt University Medical Center. Dr. Bess’s contributions to our field are numerous, including serving as president of the American Academy of Audiology, writing numerous book chapters and textbooks, and, for over 20 years, chairing one of the outstanding audiology training programs in the nation. In recent years, he’s also become known as one of audiology’s (if not the world’s) top fly fishermen. As you read Fred’s excellent summary article, you may reach the same conclusion that I did. When it comes to hearing loss in children, “minimal” is not always so minimal. Gus Mueller, Editor Page Ten
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The Hearing Journal
School-aged children with minimal sensorineural hearing loss By Fred H. Bess
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What is your definition of minimal sensorineural hearing loss (MSHL)? We typically define minimal sensorineural hearing loss for three distinct groups of children: children with unilateral sensorineural hearing loss (USHL), children with bilateral sensorineural hearing loss (BSHL), and children with high-frequency sensorineural hearing loss (HFSHL). USHL is defined as an average (500 Hz, 1000 Hz, 2000 Hz) pure-tone threshold of 20 dB HL or greater in the impaired ear. BSHL is defined as an average pure-tone threshold between 20 dB and 40 dB bilaterally. HFSHL is defined as pure-tone thresholds greater than 25 dB HL at two or more frequencies above 2000 Hz (3000 Hz, 4000 Hz, 6000 Hz, 8000 Hz) in one or both ears.
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Given your definition, what is the prevalence of MSHL? The prevalence of MSHL in the schools is 5.4%. That’s more than one out of every twenty, which means that about 2.5 million school-aged children exhibit MSHL.
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Does the prevalence of MSHL increase with age? To some extent, yes. However, the prevalence of MSHL will vary depending upon the region in which the testing was conducted and the definition of MSHL used. In our investigation, MSHL increased only slightly with increasing grade.1
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When you include children with MSHL, what is the prevalence of all types of hearing loss among school-aged children? The prevalence of hearing loss in the schools almost doubles (11.3%) when children with MSHL are included. This means that more than 5 million school-age children exhibit some degree of hearing impairment.
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Do we know the etiologic basis of MSHL? No, not really. We can, however, speculate about possible factors that may contribute to MSHL. For example, we know that noise-related hearing impairment poses a serious health problem to our youth. In our research, we found that a high percentage of children in the school-age years received exposure to loud noise. Another possible explanation for the prevalence of sensorineural loss can be found in the research of Hunter and co-workers.2 Otitis-prone children can experience highfrequency hearing loss, especially if multiple intubations occur. Hunter and colleagues theorized that basal cochlear damage may occur from the transmission of bacterial products through the round window. Finally, the increase in survival rate of premature at-risk infants treated in the neonatal intensive care unit may be contributing to the milder forms of hearing impairment.
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Do children with MSHL experience educational difficulties? Yes, we believe some of them do. In our investigation, third-grade children performed more poorly on a comprehensive test of basic skills than did a group of normal-hearing counterparts. Moreover, children with MSHL exhibited a higher percentage of problems on all subtests (academics, attention, communication, participation, school behavior) of the SIFTER (the Screening Instrument For Targeting Educational Risk) as compared to normal-hearing counterparts. Page Ten
May 1999 • Vol. 52 • No. 5
The largest discrepancy between children with MSHL and children with normal hearing was on the subtest communication. The subtest communication focuses on a student’s understanding ability, vocabulary word usage skills, and storytelling abilities–all very important skills for learning in school. In fact, a child with MSHL is 4.3 times more likely to experience trouble in the area of communication than a child with normal hearing.
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Do children with MSHL progress normally through the education system? Not according to our data. In fact, 37% of children with MSHL failed at least one grade compared to a district norm rate of about 3%.
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Wow! The failure rate is quite high. What is the economic impact of such a high failure rate? The high failure rate for children with MSHL imposes a significant financial burden on the schools. There are
approximately 46 million school-age children in the United States, of whom about 2,484,000 will exhibit MSHL. Of these, 37% (919,080) will be projected to fail at least one grade. If one assumes that the average cost to educate a child for one year is $6000, the total expenditure for grade repetition exceeds $5.5 billion (919,080 x $6000 = $5,514,480,000).
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You could do a lot with 5.5 billion dollars! You sure could! You could invest that money at 6% and use the annual interest of $330 million to improve our schools. In part, this would mean hiring more audiologists at better salaries to serve children in the schools.
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You used the COOP for looking at functional health status of children with MSHL. What is the COOP? Developed as part of the Dartmouth Cooperative Project, the COOP is a test designed to measure functional health status for school-age children in sixth
grade or above. The screening charts are based on a 5point scale with 5 representing the greatest dysfunction (see figure 1). The limited data available suggest that the charts are acceptable, reliable and valid for kids.
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Do children with MSHL experience functional problems? There is some evidence to suggest that children with MSHL have greater dysfunction in certain functional domains than children with normal hearing. For example, we noted that children with MSHL in the sixth grade had poorer self-esteem and less energy than their normal-hearing counterparts. In the ninth grade, children with MSHL had greater stress, less social support, and poorer self-esteem.
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Why would the sixth graders have less energy? It may be due to the difficulties these children experience listening under adverse conditions. Persons with hearing loss are known to expend considerable effort in processing information—especially under-
Figure 1. Sample COOP charts for use with children. 12
The Hearing Journal
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standing speech under poor acoustic conditions such as a classroom. Such a situation increases learning effort and, at the same time, depletes the energy available for performing other cognitive tasks.
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The COOP findings raise some interesting research questions concerning the psychosocial functioning of young children with hearing impairment. Do you agree? Yes, I do. Among the important questions that need to be addressed are: Does a perceived lack of social support in children with MSHL reflect an active rejection by their peers, or does it reflect ignoring or neglect by peers? What factors might underlie the poor peer relationships of children with MSHL? Does MSHL have subtle effects on language use, social interaction, or schoolwork that might attribute to lower self-esteem for some children?
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It sounds as if the COOP has some useful applications as a screening tool for children with hearing impairment. What are your thoughts on the COOP as a screening tool? Audiologists need to look more closely at the functional health status of children with hearing impairment. To this end, the COOP does appear to have potential as a screening tool for functional problems—at least for those children in sixth grade or above. The test is very safe, quick, simple, cost-effective, acceptable, and reliable. We do, however, need to conduct additional research on the validity and the predictive values of this tool. The COOP could possibly even provide useful information concerning the success of amplification as well as other intervention strategies used with this population.
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It appears as if children with MSHL have more problems than we thought. If that’s the case, why do we refer to it as a “minimal” hearing loss? Minimal implies that the problem is inconsequential. Certainly, the label “minimal” appears to be inappropriate for this population of children. Minimal does imply that no serious 14
The Hearing Journal
problem exists and that we do not need to be aggressive in the identification and management of these children. A different label for these children is needed.
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So how do you help these children? Early identification is a critical first step in the appropriate management of children with MSHL. Unfortunately, our presentday screening programs will not always pick up these children. Many of the children that we have identified with MSHL had passed previous hearing screenings. Typically, the performance characteristics of pure-tone audiometry under routine screening conditions in the schools are not very good. If we lower the cut-off criteria to identify children with MSHL, more screening errors can be expected. Perhaps the advent of hand-held otoacoustic emission systems will help us identify some of these children. Indeed, there is a need for greater emphasis on infant and school-age screening research.
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What other suggestions do you have for managing this group of children? When children have been identified with MSHL, they need to be carefully monitored audiologically over time. I recommend they receive a comprehensive audiologic evaluation every 6 to 8 months to ensure that the loss is not progressive and to pick up on additional hearing loss caused by possible conductive overlay. Moreover, the child’s speech, language, and psychosocial abilities should be monitored as well. If a child begins to experience trouble educationally, then considering the use of some form of FM technology seems appropriate. Since many of these children have difficulty understanding speech in a background of noise, the name of the game is to improve the signal-to-noise ratio reaching the child’s ear. Either a personal FM system or soundfield amplification system would be options for the audiologist to consider.
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What additional research needs to be done? The greatest problem with our study was that the N was relatively small and the response rates (compliance) of our children was only about 40%. Such limitations preclude a carte blanche interpretation of the data. Certainly, a larger sample of children with MSHL should be studied. Also, we Page Ten
need to establish the efficacy of intervention approaches advocated for this population.
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Many children with MSHL do not qualify for special education services. Is there anything we can do? Flexer3 reminds us that services for children with hearing loss in the schools are mandated by two specific laws: (1) The Education for All Handicapped Children Act of 1975 (Public Law 94-142), which was later amended and changed to the Individuals With Disabilities Education Act (IDEA), and (2) The Rehabilitation Act of 1973, Section 504. IDEA provides special education funds to develop an IEP (individualized education plan) for qualified children. However, the Rehabilitation Act, Section 504, is the most relevant legislation for these children. Because of the importance of acoustic accessibility, we can recommend FM technology for children with MSHL given that the mild loss interferes with the child’s ability to understand speech in classroom type environments.
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Any final comments? Clearly, some children with MSHL experience greater difficulty in the schools than children with normal hearing. Indeed, if we improve our efforts to identify and manage this population, it could result in a meaningful improvement in their educational performance and in their functional health status. It could also result in a substantial cost savings to the education system. At a minimum, we need to be more attentive to this somewhat invisible, yet vulnerable, population. REFERENCES 1. Bess FH, Dodd JD, Parker RA: Children with minimal sensorineural hearing loss: Prevalence, educational performance, and functional health status. Ear Hear 1998;19:339-354. 2. Hunter LL, Margolis RH, Rykken JR, et al.: High frequency hearing loss associated with otitis media. Ear Hear 1996;17:1-11. 3. Flexer C: Rationale for the use of sound-field FM amplification systems in classrooms. In Crandell CC, Smaldino JJ, and Flexer C, eds. Sound-Field FM Amplification— Theory and Practical Applications. San Diego: Singular Publishing Group, 1995: 3-16.
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