Estimated prevalence of noise-induced hearing threshold shifts among children 6 to 19 years of age: the Third National Health and Nutrition Examination Survey, 1988-1994, United States

Effectiveness of “Dangerous Decibels,” a School-Based Hearing Loss Prevention Program

Purpose

To evaluate the effectiveness of the “Dangerous Decibels” educational program in increasing students' knowledge and positively changing their attitudes and intended behaviors related to hearing and hearing loss prevention.

Method

Baseline questionnaires were completed by 478 4th-grade students and 550 7th-grade students. Approximately half of the students in each grade received a 35-min interactive classroom presentation on hearing and hearing loss prevention. The remaining students served as comparison groups. Students who received the curriculum filled out questionnaires immediately after the presentation. All students filled out follow-up questionnaires 3 months after baseline.

Results

Fourth-grade students who participated in the Dangerous Decibels presentation exhibited significant improvements in knowledge and attitudes related to hearing and hearing loss prevention. These improvements were maintained 3 months after the presentation. Seventh-grade students also experienced long-term improvements in their knowledge base. However, attitudes and intended behaviors in 7th graders returned to baseline levels 3 months postpresentation.

Conclusion

The Dangerous Decibels hearing loss prevention program was effective at producing long-term improvements in the knowledge base of 4th- and 7th-grade students. Future studies should include components on peer pressure and should incorporate repeated, multimodality interventions to increase the likelihood of long-term improvement in adolescents.

Perceived Hearing Status and Attitudes Toward Noise in Young Adults

Purpose

To estimate the prevalence of perceived hearing loss, tinnitus, and temporary threshold shift (TTS) in community college students and to see whether those students' attitudes toward noise affected their perception of their own possible hearing loss, tinnitus, and TTS.

Method

Young adults ( N = 245; age 18–27) completed 3 questionnaires: the Hearing Symptom Description, Youth Attitude to Noise Scale, and Adolescents' Habits and Hearing Protection Use.

Results

Perceived TTS and pain associated with loud noise were the most common hearing related factors, followed by perceived tinnitus and hearing loss. The students' attitudes toward noise in their daily environment showed the most negative response, whereas attitudes toward noise and concentration indicated a more positive, or less harmful, response. Chi-square analysis indicated a significant correlation between perceived hearing loss and respondents' overall attitudes toward noise exposure. Hearing protection use was limited for all participants, with the majority reporting never having used hearing protection.

Conclusion

Approximately 6% of respondents reported perceived hearing loss, and 13.5% reported prolonged tinnitus. In general, participants had neutral attitudes toward noise. Over 20% of participants reported ear pain, tinnitus, and/or TTS after noise exposure at least sometimes. Coincidentally, few participants reported consistent use of hearing protection.

Young people's exposure to loud music: a summary of the literature

OBJECTIVES

This descriptive summary of the literature provides an overview of the available studies (published before October 2006) on sociodemographic, psychosocial, and other correlates of risk and protective behaviors for hearing loss in young people aged 12 to 25 years.

METHODS

Publications were identified by a structured search in PubMed, PsycINFO, and Web of Science, and by scrutinizing the reference lists of relevant articles. The protection motivation theory was used as the theoretical framework for categorizing the psychosocial correlates.

RESULTS

Thirty-three papers were included that identified several sociodemographic and psychosocial correlates, such as age, gender, school level, ethnicity, music preference, physical activity, social influence, and free supply of hearing protection.

CONCLUSIONS

For the development of effective interventions we recommend theory-based longitudinal studies among those frequently exposed to loud music to assess these correlates in greater depth.

Variation in the normal hearing threshold predicts childhood IQ, linguistic, and behavioral outcomes

Childhood hearing level varies considerably within the range considered normal. Four classes of outcome were investigated for associations with hearing thresholds in this range: ability to identify speech in noise, neurocognitive ability, linguistic ability, and behavior. The research was conducted in a general population cohort of 711 children with mean hearing threshold of 15 dB HL or better. Some outcomes: speech in noise, intelligence, and certain linguistic abilities, were predicted in both boys and girls; effects were stronger in girls. In girls only, poorer hearing predicted worse behavior. These effects remained after statistical control for childhood socioeconomic status and otitis media. Variability in normal hearing, due to causes other than otitis media, is associated with the listening, language, and neurocognitive abilities of children, and the behavior of girls. We suggest that these effects may be present for three reasons, cochlear insults, neurodevelopmental factors, and psychological factors. We discuss how these may interact to produce the effects observed.

Noise and hearing loss: a review

BACKGROUND

Noise-induced hearing loss is a major cause of deafness and hearing impairment in the United States. Though genetics and advanced age are major risk factors, temporary and permanent hearing impairments are becoming more common among young adults and children especially with the increased exposure to portable music players. Though treatment options are limited for most people with noise-related hearing loss, several modifiable health behaviors that should begin in childhood might prevent or delay the onset of hearing impairment. The purpose of this article is to review modifiable and non-modifiable risk factors, comorbidity, and the role of health education in the prevention of noise-induced hearing loss.

METHODS

Review of current literature in the etiology, prevention, and treatment of noise-induced hearing loss as well as the role of health education.

RESULTS

Non-modifiable risk factors related to noise-related hearing loss include increasing age, genetics, male gender, and race. Modifiable risk factors are voluntary exposure to loud noise, nonuse of hearing protection, smoking, lack of exercise, poor diet, tooth loss, and the presence of diabetes and cardiovascular disease.

CONCLUSIONS

As hearing impairment among children and teenagers rises due to mostly voluntary exposure to loud noise, there are many implications for health education. Health educators need to address barriers to the use of hearing protection, deliberate exposure to loud music, and other modifiable risk factors, which cause and exacerbate hearing loss among those exposed to loud noise.

Noise Pollution: A Modern Plague

Noise is defined as unwanted sound. Environmental noise consists of all the unwanted sounds in our communities except that which originates in the workplace. Environmental noise pollution, a form of air pollution, is a threat to health and well-being. It is more severe and widespread than ever before, and it will continue to increase in magnitude and severity because of population growth, urbanization, and the associated growth in the use of increasingly powerful, varied, and highly mobile sources of noise. It will also continue to grow because of sustained growth in highway, rail, and air traffic, which remain major sources of environmental noise. The potential health effects of noise pollution are numerous, pervasive, persistent, and medically and socially significant. Noise produces direct and cumulative adverse effects that impair health and that degrade residential, social, working, and learning environments with corresponding real (economic) and intangible (well-being) losses. It interferes with sleep, concentration, communication, and recreation. The aim of enlightened governmental controls should be to protect citizens from the adverse effects of airborne pollution, including those produced by noise. People have the right to choose the nature of their acoustical environment; it should not be imposed by others.

Audiogram Notches in Noise-Exposed Workers

OBJECTIVES

Diagnostic criteria for noise-induced hearing loss include the audiometric notch, yet no standardized definition exists. This study tested whether objective notch metrics could match the clinical judgments of an expert panel.

DESIGN

A panel of occupational physicians, otolaryngologists, and audiologists reviewed audiograms of noise-exposed workers. In a two-sample process, the panel judged whether a notch was present and whether hearing loss had progressed in a notch pattern. Quantitative notch metrics were compared against expert decisions.

RESULTS

At least five of six experts agreed about notch identification in 71 and 72% of the cases in the two samples, and agreement about notch progression was 61 and 67%. Notch depth and professional specialty appeared to affect notch judgments. Despite this variability, a notch metric showed excellent agreement with expert notch consensus in each sample (94.7 and 96.6%; kappa = 0.88 and 0.92).

CONCLUSIONS

Audiogram notch metrics can agree with expert clinical consensus and assist in the surveillance of noise-exposed workers.

A recessive Mendelian model to predict carrier probabilities of DFNB1 for nonsyndromic deafness

Mutations in the DFNB1 locus, where two connexin genes are located (GJB2 and GJB6), account for half of congenital cases of nonsyndromic autosomal recessive deafness. Because of the high frequency of DFNB1 gene mutations and the availability of genetic diagnostic tests involving these genes, they are the best candidates to develop a risk prediction model of being hearing impaired. People undergoing genetic counseling are normally interested in knowing the probability of having a hearing impaired child given his/her family history. To address this, a Mendelian model that predicts the probability of being a carrier of DFNB1 mutations, using family history of deafness, has been developed. This probability will be useful as additional information to decide whether or not a genetic test should be performed. This model incorporates Mendelian mode of inheritance, the age of onset of the disease, and the current age of hearing family members. The carrier probabilities are obtained using Bayes' theorem, in which mutation prevalence is used as the prior distribution. We have validated our model by using information from 305 families affected with congenital or progressive nonsyndromic deafness, in which genetic analysis of GJB2 and GJB6 had already been performed. This model works well, especially in homozygous carriers, showing a high discriminative power. This indicates that our proposed model can be useful in the context of clinical counseling of autosomal recessive disorders.

Trends in the Prevalence of Hearing Loss Among Young Adults Entering An Industrial Workforce 1985 to 2004

OBJECTIVES

Studies have suggested that hearing loss due to recreational noise exposure may be on the rise among adolescents and young adults. This study examines whether the hearing status of young US adults entering an industrial workforce has worsened over the past 20 yr.

DESIGN

The baseline audiograms of 2526 individuals ages 17 to 25 beginning employment at a multisite US corporation between 1985 and 2004 were analyzed to determine the yearly prevalence of hearing loss.

RESULTS

Approximately 16% of the young adults in the sample had high frequency hearing loss (defined as hearing thresholds greater than 15 dB in either ear at 3,4, or 6 kHz). In a linear regression model, this prevalence decreased over the 20-yr period (odds ratio (OR) = 0.96, 95% confidence interval (CI): 0.94, 0.99). Almost 20% of subjects had audiometric "notches" consistent with noise exposure; this rate remained constant over the 20 yr, as did the prevalence (5%) of low frequency hearing loss.

CONCLUSIONS

These results indicate that despite concern about widespread recreational noise exposures, the prevalence of hearing loss among a group of young US adults has not significantly increased over the past two decades.

Hearing ability according to screening at conscription; comparison with earlier reports and with previous screening results for individuals without known ear disease

OBJECTIVE

(1) To study if young, Swedish men have poorer or better hearing according to screening at conscription in 1988 compared to 1969-1977. (2) To study how the results of screening and audiometry vary across the teenage years for a group of boys without middle ear disease.

METHOD

A birth cohort has earlier been well documented regarding results in four general screenings with follow-up and examinations and treatment for middle ear disease at the ENT departments in the area. Their results when screened at conscription have been compared with those in earlier reports on screening of Swedish conscripts. We have also studied results in screenings and follow-up at 11 and 14 years of age with special focus on small losses at the frequencies of 3, 4, 6 and 8 kHz and describe how 611 boys without known ear disease performed in these examinations and in screening at the age of 18.

RESULTS

There is no obvious trend in the prevalence of hearing loss in Swedish conscripts. At 11 years of age 80.4% and at 14 years of age 64.6% of small high tone losses diagnosed by screening were not confirmed by audiometry. Approximately half of those who had confirmed losses had normal screening at conscription.

CONCLUSIONS

18-year-old Swedish boys did not have poorer hearing in 1998 than 29 years earlier. Information drawn from screenings must be interpreted with caution.

The association between short stature and sensorineural hearing loss

In order to test the Thrifty Phenotype Hypothesis on hearing, data from two cross-sectional studies on hearing were re-evaluated. The data sets comprised 500 18-year-old conscripts, and 483 noise-exposed male employees. Sensorineural hearing loss (SNHL) was over-represented among conscripts with a short stature (odds ratio=2.2) or hearing loss in the family (odds ration=4.2), but not among noise-exposed conscripts (odds ratio=0.9-1.3). Among noise-exposed short employees, hypertension and age exhibited a negative impact on high frequency hearing thresholds, while among tall employees hypertension had no effect on hearing and the influence of age was less pronounced (p<0.01 for body height; p<0.02 for age, hypertension and the interaction between body height and hypertension; p<0.05 for the interaction between body height and age). This suggests that mechanisms linked to fetal programming and growth retardation and/or insulin-like growth factor 1 levels during fetal life, such as a delayed cell cycle during the time window when the cochlea develops, may cause SNHL in adulthood.

Compounds for the prevention and treatment of noise-induced hearing loss

Noise-induced hearing loss (NIHL) is the leading occupational disease and a major contributor to the development of age-related hearing loss. The pharmacological prevention and treatment of NIHL has been under preclinical investigation for the past 20 years. Promising treatments have now been identified and entered into clinical development. Within the next five years, safe and effective drugs could be approved as the first generation of otoprotectants. This review covers strategies that are under investigation for NIHL. Drugs that effectively prevent and treat NIHL will have a significant impact on medical costs, disability compensation and several issues affecting the quality of life.

Führt eine Schallpegelabsenkung in Diskotheken zu einem Rückgang der Besucher?

BACKGROUND

This study investigated whether adolescents are likely to decrease their frequency of discotheque attendance if the sound levels are lowered moderately.

METHODS

A sample of 1,213 high school students aged between 13 and 20 years (mean: 15.8 years) were given a questionnaire and asked their views on the current sound levels at discotheques, and whether they would change their attendance if the levels were somewhat lower.

RESULTS

Some 53.7% of the respondents wished to keep the current sound levels, while only 2.5% preferred a raise, and 43.8% a decrease. In the case of a moderate decrease, 85% of respondents would not change their frequency of discotheque attendance, while 5% would reduce it, and 10% would increase it.

CONCLUSIONS

The results of this study contradict the fears of discotheque operators that adolescents would visit the discotheque less frequently if the sound levels are lowered moderately. To prove the effects of a sound level reduction, however, separate studies are needed.

Prevalence of Hearing Impairment in a Rural Midwestern Cohort: Estimates from the Keokuk County Rural Health Study, 1994 to 1998

OBJECTIVE

The current paper estimates the prevalence of hearing problems in a rural population, analyzes the prevalence of hearing problems across age groups, and compares the prevalence of hearing problems in this population with results obtained in other populations.

DESIGN

Data were obtained from a random sample of the residents of a rural county, stratified by farm, rural non-farm, and town residence. Hearing test results were obtained from participants between the ages of 8 and 92 years (N = 1972; 47% male). Pure-tone thresholds were classified as normal or impaired using a number of metrics, including speech intelligibility index values. Selected comparisons of crude rates were made with previous population-based studies of hearing loss prevalence.

RESULTS

Nearly all (99%) of the participants in this study had significant hearing impairment. Atypical hearing impairment is most prevalent at 6 kHz. In males, this excess impairment shifts to lower frequencies with age but monotonically decreases in females. Notched configurations were most common among those between 30 and 59 years old. In females, the prevalence of hearing impairments sufficient to interfere with speech understanding begins to rapidly increase in the 6th decade (4th decade in males). Comparisons with prior population-based studies in the United States and Great Britain identified few significant differences.

CONCLUSIONS

Significant hearing impairment is common in rural populations. The high prevalence in this population is similar to that found in other population-based studies. Future studies are needed to examine (1) the risk factors for hearing impairment, (2) the natural course of hearing problems across the life span, and (3) the effect of programs for the prevention of hearing impairment and rehabilitation for persons with existing hearing impairments.

Evaluation of noise-induced hearing loss in young people using a web-based survey technique

OBJECTIVE

Many adolescents and young adults consciously expose themselves to loud music for entertainment. We hypothesized that these individuals might not be aware that exposure to loud music could result in hearing loss. Furthermore, we wished to assess the feasibility of a web-based survey to collect health information from this group.

METHODS

A 28-question survey was designed to target adolescents and young adults. The survey contained questions about views toward general health issues, including hearing loss, and was presented to random visitors at the MTV web site.

RESULTS

In 3 days, 9693 web surveys were completed. Hearing loss was defined on a Likert scale as "a very big problem" by 8% of respondents compared with other health issues: sexually transmitted diseases, 50%; alcohol/drug use, 47%; depression, 44%; smoking, 45%; nutrition and weight issues, 31%; and acne, 18%. Notably, most respondents had experienced tinnitus or hearing impairment attending concerts (61%) and clubs (43%). Only 14% of respondents had used earplugs; however, many could be motivated to try ear protection if they were aware of the potential for permanent hearing loss (66%) or were advised by a medical professional (59%).

CONCLUSIONS

A majority of young adults have experienced tinnitus and hearing impairment after exposure to loud music. Fortunately, many of these individuals could be motivated to wear ear protection. This novel web-based survey technique rapidly generated a large database and is a feasible method to obtain health data from this group.

Sensorineural hearing loss in children

During the past three to four decades, the incidence of acquired sensorineural hearing loss (SNHL) in children living in more developed countries has fallen, as a result of improved neonatal care and the widespread implementation of immunisation programmes. The overall decrease has been accompanied by a relative increase in the proportion of inherited forms of SNHL. The contribution made by one gene in particular, GJB2, to the genetic load of SNHL has strongly affected the assessment and care of children with hearing loss. These changes in the incidence of SNHL have not been seen in children living in less developed countries, where the prevalence of consanguinity is high in many areas, and both genetic and acquired forms of SNHL are more common, particularly among children who live in poverty. Focused genetic counselling and health education might lead to a decrease in the prevalence of inherited SNHL in these countries. Establishment of vaccination programmes for several vaccine-preventable infectious diseases would reduce rates of acquired SNHL. Although the primary purpose of such programmes is the prevention of serious and in many cases fatal infections, a secondary benefit would be a reduction in disease-related complications such as SNHL that cause permanent disability in survivors.

Trends in hearing impairment in United States adults: the national health interview survey, 1986-1995

BACKGROUND

United States trends in the prevalence of hearing impairment have not been reported. These trends could be rising due to changes in environmental noise exposure; alternatively, rates could be declining via a compression of morbidity hypothesis that has been postulated to be occurring in older adults residing in developed nations.

METHODS

The National Health Interview Survey is a continuous multistage area probability survey of the U.S. civilian noninstitutionalized population living at addressed dwellings. Adults within randomly selected households were administered a chronic conditions list that included questions about hearing impairment. Complete data were available on 107,100 white and 17,904 African-American adults aged 18 years and older in survey years 1986-1995. Race-specific rates of hearing impairment were adjusted for age and sample survey design.

RESULTS

Annual age-adjusted rates of some hearing impairment ranged from 11.0% to 12.7% in whites and 5.9% to 8.5% in African Americans. Rates of severe bilateral hearing impairment in these race groups were 0.7% to 1.1% and 0.1% to 0.5%, respectively. There was no evidence of change in rates of hearing impairment among participants stratified by race and 10-year age groups.

CONCLUSIONS

Reported rates of hearing impairment remained relatively stable in the U.S. noninstitutionalized population from 1986 to 1995. There was no evidence of change in rates in adults grouped into 10-year age groups. Population-based studies designed to include clinical and self-reported measures of hearing impairment are needed to further examine trends in hearing impairment.

Mean and median hearing thresholds among children 6 to 19 years of age: the Third National Health And Nutrition Examination Survey, 1988 to 1994, United States

OBJECTIVE

The objective of this study was to provide the first national representative values for mean and median hearing thresholds among US children 6 to 19 yrs of age.

METHODS

Hearing thresholds were obtained from 6166 children in the Third National Health and Nutrition Examination Survey (1988 to 1994), a national, population-based cross-sectional survey with household interview and audiometric testing at 0.5 to 8 kHz. Means, medians, and standard errors of the mean were obtained and reported by ear, frequency, sex, and age.

RESULTS

The mean and median thresholds ranged from 3.0 to 11.8 dB HL and -1.0 to 10.8 dB HL, respectively. The highest (poorest) thresholds were obtained at test frequencies above 4000 Hz. Similar mean and median thresholds were found between boys and girls at all frequencies.

CONCLUSIONS

These data indicate that the mean thresholds fall below the standard screening guidelines recommended by the American Speech-Language-Hearing Association (< or =20 dB HL for the frequencies from 1000< or =20 dB HL for the frequencies from 2000, and 4000 Hz). The results of this study suggest the need to include the test frequency of 6000 Hz in screening protocols for children.

Output Levels of Commercially Available Portable Compact Disc Players and the Potential Risk to Hearing

OBJECTIVE

To measure the sound levels generated by the headphones of commercially available portable compact disc players and provide hearing healthcare providers with safety guidelines based on a theoretical noise dose model.

DESIGN

Using a Knowles Electronics Manikin for Acoustical Research and a personal computer, output levels across volume control settings were recorded from headphones driven by a standard signal (white noise) and compared with output levels from music samples of eight different genres. Many commercially available models from different manufacturers were investigated. Several different styles of headphones (insert, supra-aural, vertical, and circumaural) were used to determine if style of headphone influenced output level.

RESULTS

Free-field equivalent sound pressure levels measured at maximum volume control setting ranged from 91 dBA to 121 dBA. Output levels varied across manufacturers and style of headphone, although generally the smaller the headphone, the higher the sound level for a given volume control setting. Specifically, in one manufacturer, insert earphones increased output level 7-9 dB, relative to the output from stock headphones included in the purchase of the CD player. In a few headphone-CD player combinations, peak sound pressure levels exceeded 130 dB SPL.

CONCLUSIONS

Based on measured sound pressure levels across systems and the noise dose model recommended by National Institute for Occupational Safety and Health for protecting the occupational worker, a maximum permissible noise dose would typically be reached within 1 hr of listening with the volume control set to 70% of maximum gain using supra-aural headphones. Using headphones that resulted in boosting the output level (e.g., insert earphones used in this study) would significantly decrease the maximum safe volume control setting; this effect was unpredictable from one manufacturer to another. In the interest of providing a straightforward recommendation that should protect the hearing of the majority of consumers, reasonable guidelines would include a recommendation to limit headphone use to 1 hr or less per day if using supra-aural style headphones at a gain control setting of 60% of maximum.

Nongenetic causes of hearing loss

Nongenetic as well as genetic etiologies must be explored in the child with identified hearing loss. Graduates of the neonatal intensive care unit are at increased risk for developing hearing loss due to hypoxia, hyperbilirubinemia, very low birth weight, and ototoxic medications. Although meningitis has decreased in frequency, it is still a risk factor for hearing loss. Cytomegalovirus remains the most common congenital infection and a relatively common etiology of hearing loss, which can be progressive. Preventable causes of hearing loss include those caused by head trauma, noise, and ototoxic medications. Identification of the etiology of hearing loss can facilitate the development of a treatment and management plan.

The importance of hearing conservation instruction

According to Denehy (1999), "school nurses can play a powerful role in promoting health in their schools and community." She encouraged school nurses to "Take and make opportunities to promote health in the classroom" (p. 4). Classroom presentation of hearing conservation information is one way for school nurses to promote health and to reduce the prevalence of noise-induced hearing loss (NIHL), an irreversible yet preventable condition. Because of excessive sound exposure, the prevalence of NIHL among children is increasing. Numerous experts have recommended the implementation of hearing conservation education programs in schools. Despite these recommendations made over the last 3 decades, basic hearing conservation information that could prevent countless cases of NIHL remains conspicuously absent from most school curricula. School nurses should seize this "golden opportunity" to promote health in the classroom and help to reduce the prevalence of NIHL.

Screening and prevention of hearing loss in children

Congenital hearing loss is the most common neurosensory handicap in neonates. Recently, technology has become available that has allowed states to implement universal screening programs at a relatively low cost and with minimal expertise needed for hospital personnel to operate the screening machines. In successful programs, the age of diagnosis has been reduced from 2(1/2) years to 3 to 6 months. Children diagnosed with hearing loss before speech develops have been shown to have better speech and language outcomes than those who are diagnosed later. Strategies for screening and early intervention are discussed, as well as the causes, prevention, and treatment of more common forms of childhood hearing loss.

Preventing noise-induced hearing loss

Noise-induced hearing loss is a significant, irreversible impairment, but one that is preventable. The numbers of persons, including children, exposed to high noise is increasing, necessitating the use of hearing protection if the noise cannot be reduced to a safe level. The effectiveness of interventions has been tested with select worker groups, but use of hearing protection continues to be less than necessary when in workers are exposed to high noise. Clinicians have an essential role in educating clients of all ages about this problem and in assisting them in protecting their hearing.

Hearing conservation education programs for children: a review

Prevalence of noise-induced hearing loss (NIHL) among children is increasing. Experts have recommended implementation of hearing conservation education programs in schools. Despite these recommendations made over the past three decades, basic hearing conservation information that could prevent countless cases of NIHL remains absent from most school curricula. This paper reviews existing hearing conservation education programs and materials designed for children or that could be adapted for classroom use. This information will be useful as a resource for educators and school administrators and should encourage further development, implementation, and dissemination of hearing conservation curricula. The overall, and admittedly ambitious, goal of this review is to facilitate implementation of hearing conservation curricula into all US schools on a continuing basis. Ultimately, implementation of such programs should reduce the prevalence of noise-induced hearing loss among children and adults.