Prevalence of noise-induced hearing-threshold shifts and hearing loss among US youths

Protection from noise-induced hearing loss with Src inhibitors

Noise-induced hearing loss is a major cause of acquired hearing loss around the world and pharmacological approaches to protecting the ear from noise are under investigation. Noise results in a combination of mechanical and metabolic damage pathways in the cochlea. The Src family of protein tyrosine kinases could be active in both pathways and Src inhibitors have successfully prevented noise-induced cochlear damage and hearing loss in animal models. The long-term goal is to optimize delivery methods into the cochlea to reduce invasiveness and limit side-effects before human clinical testing can be considered. At their current early stage of research investigation, Src inhibitors represent an exciting class of compounds for inclusion in a multifaceted pharmacological approach to protecting the ear from noise.

Auditory risk estimates for youth target shooting

OBJECTIVE

To characterize the impulse noise exposure and auditory risk for youth recreational firearm users engaged in outdoor target shooting events. The youth shooting positions are typically standing or sitting at a table, which places the firearm closer to the ground or reflective surface when compared to adult shooters.

DESIGN

Acoustic characteristics were examined and the auditory risk estimates were evaluated using contemporary damage-risk criteria for unprotected adult listeners and the 120-dB peak limit suggested by the World Health Organization (1999) for children.

STUDY SAMPLE

Impulses were generated by 26 firearm/ammunition configurations representing rifles, shotguns, and pistols used by youth. Measurements were obtained relative to a youth shooter's left ear.

RESULTS

All firearms generated peak levels that exceeded the 120 dB peak limit suggested by the WHO for children. In general, shooting from the seated position over a tabletop increases the peak levels, LAeq8 and reduces the unprotected maximum permissible exposures (MPEs) for both rifles and pistols. Pistols pose the greatest auditory risk when fired over a tabletop.

CONCLUSION

Youth should utilize smaller caliber weapons, preferably from the standing position, and always wear hearing protection whenever engaging in shooting activities to reduce the risk for auditory damage.

Current office-based hearing screening questions fail to identify adolescents at risk for hearing loss

OBJECTIVE

There is a rising prevalence of hearing loss among adolescents in the United States. Current paediatric preventive care recommendations by the Bright Futures guidelines and the American Academy of Pediatrics suggest that clinicians should ask adolescents ten hearing screening questions to identify those who are at high risk of hearing loss for further objective hearing testing. We assessed the utility of these subjective risk assessment questions to distinguish those adolescents with objectively documented hearing loss.

SETTING

A single public high school in Pennsylvania.

METHODS

We compared results from a prospective study evaluating objective hearing assessments with the use of the ten Bright Futures hearing screening questions plus additional adolescent-specific questions to predict adolescent hearing loss.

RESULTS

In relation to the questions used in this study, adolescents who were referred following objective hearing screens were more likely to report "trouble following the conversation when two or more people are talking at the same time" and a "past experience of slight hearing loss". Referrals from sound treated booth testing were more likely to report "trouble hearing over the phone" and have a diagnosis or history of hearing loss.

CONCLUSIONS

Most Bright Futures questions were not associated with adolescent hearing loss. An objective adolescent hearing screen should be considered in the recommended schedule of preventive care, instead of the current risk-based subjective assessment.

Personally Modifiable Risk Factors Associated with Pediatric Hearing Loss: A Systematic Review

BACKGROUND

Pediatric hearing loss is an increasingly recognized problem with significant implications. Increasing our quantitative understanding of potentially modifiable environmental risk factors for hearing loss may form the foundation for prevention and screening programs.

OBJECTIVE

To determine whether specific threshold exposure levels of personally modifiable risk factors for hearing loss have been defined, with the overarching goal of providing actionable guidance for the prevention of pediatric hearing loss.

DATA SOURCES

A systematic review was performed. Computerized searches of PubMed, EMBASE, and the Cochrane Library were completed and supplemented with manual searches.

REVIEW METHODS

Inclusion/exclusion criteria were designed to determine specific threshold values of personally modifiable risk factors on hearing loss in the pediatric population. Searches and data extraction were performed by independent reviewers.

RESULTS

There were 38 criterion-meeting studies, including a total of 50,651 subjects. Threshold noise exposures significantly associated with hearing loss in youth included: (1) more than 4 hours per week or more than 5 years of personal headphone usage, (2) more than 4 visits per month to a discotheque, and (3) working on a mechanized farm. Quantified tobacco levels of concern included any level of in utero smoke exposure as well as secondhand exposure sufficient to elevate serum cotinine.

CONCLUSIONS

Specific thresholds analyses are limited. Future studies would ideally focus on stratifying risk according to clearly defined levels of exposure, in order to provide actionable guidance for children and families.

Associations between dietary quality, noise, and hearing: data from the National Health and Nutrition Examination Survey, 1999-2002

OBJECTIVE

A statistically significant relationship between dietary nutrient intake and threshold sensitivity at higher frequencies has been reported, but evidence conflicts across studies. Here, the potential interaction between noise and diet in their association to hearing was examined.

DESIGN

This cross-sectional analysis was based on Healthy Eating Index data and audiological threshold pure-tone averages for low (0.5 to 2 kHz) and high (3 to 8 kHz) frequencies.

STUDY SAMPLE

Data were drawn from the National Health and Nutrition Examination Survey, 1999-2002.

RESULTS

Controlling for age, sex, race/ethnicity, education, diabetes, hypertension, and smoking we found statistically significant relationships between dietary quality and high-frequency threshold sensitivity as well as noise exposure and high-frequency thresholds. In addition, there was a statistically significant interaction between dietary quality and reported noise exposure with respect to high-frequency threshold sensitivity in participants, where greater reported noise exposure and poorer diet were associated with poorer hearing (p's < 0.05).

CONCLUSIONS

The current findings support an association between healthier eating and better hearing at higher frequencies; the strength of this relationship varied as a function of participant noise history, with the most robust relationship in those that reported military service or firearm use.

Role of cysteinyl leukotriene signaling in a mouse model of noise-induced cochlear injury

Noise-induced hearing loss is one of the most common types of sensorineural hearing loss. In this study, we examined the expression and localization of leukotriene receptors and their respective changes in the cochlea after hazardous noise exposure. We found that the expression of cysteinyl leukotriene type 1 receptor (CysLTR1) was increased until 3 d after noise exposure and enhanced CysLTR1 expression was mainly observed in the spiral ligament and the organ of Corti. Expression of 5-lipoxygenase was increased similar to that of CysLTR1, and there was an accompanying elevation of CysLT concentration. Posttreatment with leukotriene receptor antagonist (LTRA), montelukast, for 4 consecutive days after noise exposure significantly decreased the permanent threshold shift and also reduced the hair cell death in the cochlea. Using RNA-sequencing, we found that the expression of matrix metalloproteinase-3 (MMP-3) was up-regulated after noise exposure, and it was significantly inhibited by montelukast. Posttreatment with a MMP-3 inhibitor also protected the hair cells and reduced the permanent threshold shift. These findings suggest that acoustic injury up-regulated CysLT signaling in the cochlea and cochlear injury could be attenuated by LTRA through regulation of MMP-3 expression. This study provides mechanistic insights into the role of CysLTs signaling in noise-induced hearing loss and the therapeutic benefit of LTRA.

Hearing loss prevention education using adopt-a-band: changes in self-reported earplug use in two high school marching bands

PURPOSE

Hearing loss prevention has always been an important issue for audiologists. The importance of hearing loss prevention education for young musicians is now recognized by the National Association for Music Education as well as the National Association of Schools of Music. Adopt-a-Band is a commercial program designed to foster hearing loss prevention behavior in young musicians.

METHOD

This study assessed changes in earplug use, measured using self-report surveys, after Adopt-a-Band training. Participants were members of 2 high school marching bands who viewed an informational DVD and reviewed fact sheets. Flat-attenuation earplugs were distributed, and training was provided. In addition, study participants engaged in discussion of hearing loss with a doctor of audiology student.

RESULTS

Before training, 23% of participants reported they had previously used hearing protection. Immediately after training, 94% of participants reported they planned to use hearing protection at least occasionally. In a final end-of-season survey, earplug use had reliably increased; 62% of participants reported they used earplugs at least occasionally.

CONCLUSIONS

Earplug use increased, but self-reported behavioral change was not as robust as predicted from self-reported participant intentions. Participant comments regarding factors that influenced their earplug use decisions suggest opportunities to improve training.

Beyond obesity and lifestyle: a review of 21st century chronic disease determinants

The obesity epidemic and associated chronic diseases are often attributed to modern lifestyles. The term "lifestyle" however, ignores broader social, economic, and environmental determinants while inadvertently "blaming the victim." Seen more eclectically, lifestyle encompasses distal, medial, and proximal determinants. Hence any analysis of causality should include all these levels. The term "anthropogens," or "…man-made environments, their by-products and/or lifestyles encouraged by these, some of which may be detrimental to human health" provides a monocausal focus for chronic diseases similar to that which the germ theory afforded infectious diseases. Anthropogens have in common an ability to induce a form of chronic, low-level systemic inflammation ("metaflammation"). A review of anthropogens, based on inducers with a metaflammatory association, is conducted here, together with the evidence for each in connection with a number of chronic diseases. This suggests a broader view of lifestyle and a focus on determinants, rather than obesity and lifestyle per se as the specific causes of modern chronic disease. Under such an analysis, obesity is seen more as "a canary in a mineshaft" signaling problems in the broader environment, suggesting that population obesity management should be focused more upstream if chronic diseases are to be better managed.

Using prophylactic antioxidants to prevent noise-induced hearing damage in young adults: a protocol for a double-blind, randomized controlled trial

Background

During leisure activities young people are often exposed to excessive noise levels resulting in an increase of noise-induced symptoms such as hearing loss, tinnitus and hyperacusis. Noise-induced tinnitus is often perceived after loud music exposure and provides an important marker for overexposure as a temporary threshold shift that is often not experienced by the individual itself. As oxidative stress plays an important role in the pathogenesis of noise-induced hearing loss, the use of antioxidants to prevent hearing damage has recently become the subject of research.

Methods

This study proposes a randomized, double-blind, placebo-controlled crossover trial to assess the effects of a prophylactic combination of N-acetylcysteine (600 mg) and magnesium (200 mg) prior to leisure noise exposure in young adults. The primary outcome measure is the tinnitus loudness scored by a visual analogue scale (VAS). Secondary outcome measures are the differences in audiological measurements for the antioxidant treatments compared to placebo intake. Audiological testing comprising of pure tone audiometry including frequencies up to 16 kHz, distortion product otoacoustic emissions, transient-evoked otoacoustic emissions and speech-in-noise testing will be performed prior to and within 7 hours after noise exposure. By use of a mixed effects statistical model, the effects of antioxidants compared to placebo intake will be assessed.

Discussion

As adolescents and young adults often do not use hearing protection while being exposed to loud music, the use of preventive antioxidant intake may provide a useful and harmless way to prevent noise-induced hearing damage in this population. Furthermore, when exposed to hazardous noise levels the protection provided by hearing protectors might not be sufficient to prevent hearing damage and antioxidants may provide additive otoprotective effects. Previous research mainly focused on occupational noise exposure. The present study provides a protocol to assess the usefulness of antioxidants during leisure noise activities.

Trial registration

The present protocol is registered at ClinicalTrials.gov: NCT01727492.

Effectiveness of a preventive campaign for noise-induced hearing damage in adolescents

OBJECTIVES

Many studies have documented a high incidence of hearing loss and tinnitus in adolescents after recreational noise exposure. The prevalence of noise-induced symptoms is in contradiction to the low preventive use of hearing protection. The effects of preventive campaigns on the attitudes toward noise in young people are under debate. The aim of the present study is to investigate whether a preventive campaign can alter attitudes toward noise in adolescents and whether this results in an increase of hearing protection use in this population.

METHODS

A cohort of 547 Flemish high school students, aged 14 to 18 years old, completed a questionnaire prior to and after a governmental campaign focusing on the harmful effects of recreational noise and the preventive use of hearing protection. At both occasions the attitudes toward noise and toward hearing protection were assessed by use of the youth attitudes toward noise scale (YANS) and the beliefs about hearing protection and hearing loss (BAHPHL), respectively. These questionnaires fit into the model of the theory of planned behavior which provides a more clear insight into the prediction of a certain behavior and the factors influencing that behavior.

RESULTS

The score on the YANS and the BAHPHL decreased significantly (p < 0.001) implying a more negative attitude toward noise and a more positive attitude toward hearing protection. The use of hearing protection increased significantly from 3.6% prior to the campaign to 14.3% (p = 0.001) post campaign in students familiar with the campaign.

CONCLUSIONS

Measurable alteration of all the variables in the theory of planned behavior caused an increase of the intentions to use hearing protection as well as the actual use of hearing protection. The present study shows the usefulness of the theory of planned behavior to change and guide adolescents' preventive actions toward noise damage. In addition, preventive campaigns can establish attitude and behavioral adjustments. However, the long term effects of preventive campaigns should be investigated in future research.

Tinnitus pitch and minimum masking levels in different etiologies

OBJECTIVE

We sought to determine whether the results of audiological tests and tinnitus characteristics, particularly tinnitus pitch and minimum masking level (MML), depend on tinnitus etiology, and what other etiology-specific tinnitus characteristics there are.

DESIGN

The patients answered questions concerning tinnitus laterality, duration, character, aggravation, alleviation, previous treatment, and circumstances of onset. The results of tympanometry, pure-tone audiometry, distortion-product otoacoustic emissions, tinnitus likeness spectrum, MML, and uncomfortable loudness level were evaluated.

STUDY SAMPLE

Patients with several tinnitus etiological factors were excluded. The remaining participants were divided into groups according to medical history: acute acoustic trauma: 67 ears; chronic acoustic trauma: 82; prolonged use of oral estrogen and progesterone contraceptives: 46; Ménière's disease: 25; congenital hearing loss: 19; sensorineural sudden deafness: 40; dull head trauma: 19; viral labyrinthitis: 53; stroke: 6; presbycusis: 152. Data of 509 ears were analysed.

RESULTS

Tinnitus pitch was highest in patients with acute acoustic trauma and lowest in patients receiving estrogen and progesterone. MML was lowest after acute acoustic trauma and in congenital hearing loss, and highest after a stroke and in the case of presbytinnitus.

CONCLUSIONS

Tinnitus pitch and MML are etiology dependent.

Societal-level Risk Factors Associated with Pediatric Hearing Loss: A Systematic Review

OBJECTIVE

To determine if the current body of evidence describes specific threshold values of concern for modifiable societal-level risk factors for pediatric hearing loss, with the overarching goal of providing actionable guidance for the prevention and screening of audiological deficits in children.

DATA SOURCES

Three related systematic reviews were performed. Computerized PubMed, Embase, and Cochrane Library searches were performed from inception through October 2013 and were supplemented with manual searches.

REVIEW METHODS

Inclusion/exclusion criteria were designed to determine specific threshold values of societal-level risk factors on hearing loss in the pediatric population. Searches and data extraction were performed by independent reviewers.

RESULTS

There were 20 criterion-meeting studies with 29,128 participants. Infants less than 2 standard deviations below standardized weight, length, or body mass index were at increased risk. Specific nutritional deficiencies related to iodine and thiamine may also increase risk, although data are limited and threshold values of concern have not been quantified. Blood lead levels above 10 µg/dL were significantly associated with pediatric sensorineural loss, and mixed findings were noted for other heavy metals. Hearing loss was also more prevalent among children of socioeconomically disadvantaged families, as measured by a poverty income ratio less than 0.3 to 1, higher deprivation category status, and head of household employment as a manual laborer.

CONCLUSIONS

Increasing our understanding of specific thresholds of risk associated with causative factors forms the foundation for preventive and targeted screening programs as well as future research endeavors.

FVB/NJ mice demonstrate a youthful sensitivity to noise-induced hearing loss and provide a useful genetic model for the study of neural hearing loss

The hybrid mouse diversity panel (HMDP), a panel of 100 strains, has been employed in genome wide association studies (GWAS) to study complex traits in mice. Hearing is a complex trait and the CBA/CaJ mouse strain is a widely used model for age-related hearing loss (ARHI) and noise induced hearing loss (NIHL). The CBA/CaJ strain's youthful sensitivity to noise and limited age-related loss led us to attempt to identify additional strains segregating a similar phenotype for our panel. FVB/NJ is part of the HMDP and has been previously described as having a similar ARHI phenotype to CBA/CaJ. For these reasons, we have studied the FVB/NJ mouse for ARHI and NIHL phenotypes in hopes of incorporating its phenotype into HMDP studies. We demonstrate that FVB/NJ exhibits ARHI at an earlier age than CBA/CaJ and young FVB/NJ mice are vulnerable to NIHL up until 10 to 12 weeks. This suggests that FVB/NJ may be used as an additional genetic model for neural forms of progressive hearing loss and for the study of youthful sensitivity to noise.

Assessment of Noise Exposure to Children: Considerations for the National Children's Study

Evidence has been accruing to indicate that young children are vulnerable to noise in their physical environment. A literature review identified that, in addition to hearing loss, noise exposure is associated with negative birth outcomes, reduced cognitive function, inability to concentrate, increased psychosocial activation, nervousness, feeling of helplessness, and increased blood pressure in children. While increasing attention has been given to the health effects of noise in children, research about noise exposure is sparse and often the measure of exposure is simply proximity to a noise source. The U.S. National Children's Study (NCS) provides a unique opportunity to investigate noise exposures to pregnant women and children using a number of assessment modalities at different life stages. Measurement of noise levels in homes and other environments, personal dosimetry measurements made over a period of days, and questionnaires addressing sources of noise in the environment, annoyance to noise, perceived noise level, use of head phones and ear buds, noisy activity exposures, and occupational exposures, are planned for evaluation within the NCS Vanguard pilot study. We describe the NCS planned approach to addressing noise exposure assessment in study visits over a child's lifetime.

Noise producing toys and the efficacy of product standard criteria to protect health and education outcomes

An evaluation of 28 commercially available toys imported into New Zealand revealed that 21% of these toys do not meet the acoustic criteria in the ISO standard, ISO 8124-1:2009 Safety of Toys, adopted by Australia and New Zealand as AS/NZS ISO 8124.1:2010. While overall the 2010 standard provided a greater level of protection than the earlier 2002 standard, there was one high risk toy category where the 2002 standard provided greater protection. A secondary set of toys from the personal collections of children known to display atypical methods of play with toys, such as those with autism spectrum disorders (ASD), was part of the evaluation. Only one of these toys cleanly passed the 2010 standard, with the remainder failing or showing a marginal-pass. As there is no tolerance level stated in the standards to account for interpretation of data and experimental error, a value of +2 dB was used. The findings of the study indicate that the current standard is inadequate in providing protection against excessive noise exposure. Amendments to the criteria have been recommended that apply to the recently adopted 2013 standard. These include the integration of the new approaches published in the recently amended European standard (EN 71) on safety of toys.

Extended high-frequency thresholds in college students: effects of music player use and other recreational noise

BACKGROUND

Human hearing is sensitive to sounds from as low as 20 Hz to as high as 20,000 Hz in normal ears. However, clinical tests of human hearing rarely include extended high-frequency (EHF) threshold assessments, at frequencies extending beyond 8000 Hz. EHF thresholds have been suggested for use monitoring the earliest effects of noise on the inner ear, although the clinical usefulness of EHF threshold testing is not well established for this purpose.

PURPOSE

The primary objective of this study was to determine if EHF thresholds in healthy, young adult college students vary as a function of recreational noise exposure.

RESEARCH DESIGN

A retrospective analysis of a laboratory database was conducted; all participants with both EHF threshold testing and noise history data were included. The potential for "preclinical" EHF deficits was assessed based on the measured thresholds, with the noise surveys used to estimate recreational noise exposure.

STUDY SAMPLE

EHF thresholds measured during participation in other ongoing studies were available from 87 participants (34 male and 53 female); all participants had hearing within normal clinical limits (≤25 HL) at conventional frequencies (0.25-8 kHz).

RESULTS

EHF thresholds closely matched standard reference thresholds [ANSI S3.6 (1996) Annex C]. There were statistically reliable threshold differences in participants who used music players, with 3-6 dB worse thresholds at the highest test frequencies (10-16 kHz) in participants who reported long-term use of music player devices (>5 yr), or higher listening levels during music player use.

CONCLUSIONS

It should be possible to detect small changes in high-frequency hearing for patients or participants who undergo repeated testing at periodic intervals. However, the increased population-level variability in thresholds at the highest frequencies will make it difficult to identify the presence of small but potentially important deficits in otherwise normal-hearing individuals who do not have previously established baseline data.

Epidemiology of noise-induced tinnitus and the attitudes and beliefs towards noise and hearing protection in adolescents

Background and objectives

Previous research showed an increase of noise-induced symptoms in adolescents. Permanent tinnitus as a consequence of loud music exposure is usually considered as noise-induced damage. The objective was to perform an epidemiological study in order to obtain prevalence data of permanent noise-induced tinnitus as well as temporary tinnitus following noise exposure in a young population. In addition the attitudes and beliefs towards noise and hearing protection were evaluated in order to explain the use/non-use of hearing protection in a young population.

Methods

A questionnaire was completed by 3892 high school students (mean age: 16.64 years old, SD: 1.29 years). The prevalence of temporary and permanent tinnitus was assessed. In addition the ‘Youth Attitudes to Noise Scale’ and the ‘Beliefs About Hearing Protection and Hearing Loss’ were used in order to assess the attitudes and beliefs towards noise and hearing protection respectively.

Results

The prevalence of temporary noise-induced tinnitus and permanent tinnitus in high school students was respectively 74.9% and 18.3%. An increasing prevalence of temporary tinnitus with age was present. Most students had a ‘neutral attitude’ towards loud music and the use of hearing protection was minimal (4.7%). The limited use of hearing protection is explained by a logistic regression analysis showing the relations between certain parameters and the use of hearing protection.

Conclusions

Despite the very high prevalence of tinnitus in such a young population, the rate of hearing protection use and the knowledge about the risks of loud music is extremely low. Future preventive campaigns should focus more on tinnitus as a warning signal for noise-induced damage and emphasize that also temporary symptoms can result in permanent noise-induced damage.

Estimation of permanent noise-induced hearing loss in an urban setting

The potential burden of noise-induced permanent threshold shift (NIPTS) in U.S. urban settings is not well-characterized. We used ANSI S3.44-1996 to estimate NIPTS for a sample of 4585 individuals from New York City (NYC) and performed a forward stepwise logistic regression analysis to identify predictors of NIPTS >10 dB. The average individual is projected to develop a small NIPTS when averaged across 1000-4000 Hz for 1- to 20-year durations. For some individuals, NIPTS is expected to be substantial (>25 dB). At 4000 Hz, a greater number of individuals are at risk of NIPTS from MP3 players and stereos, but risk for the greatest NIPTS is for those with high occupational and episodic nonoccupational (e.g., power tool use) exposures. Employment sector and time spent listening to MP3 players and stereos and participating in episodic nonoccupational activities associated with excessive noise levels increased the odds of NIPTS >10 dB at 4000 Hz for 20-year durations. Our results indicate that the risk of NIPTS may be substantial for NYC and perhaps other urban settings. Noise exposures from "noisy" occupational and episodic nonoccupational activities and MP3 players and stereos are important risk factors and should be a priority for public health interventions.

Obesity is associated with sensorineural hearing loss in adolescents

OBJECTIVES/HYPOTHESIS

Childhood obesity, defined as body mass index (BMI) ≥ 95%, is a significant health problem associated with a variety of disorders, and in adults it has been found to be a risk factor for hearing loss. We investigated the hypothesis that obese children are at increased risk of sensorineural hearing loss (SNHL).

STUDY DESIGN

A complex, multistage, stratified geographic area design for collecting representative data from noninstitutionalized U.S. population.

METHODS

Relevant cross-sectional data from the National Health and Nutrition Examination Survey, 2005 to 2006, for 1,488 participants 12 to 19 years of age was examined. Subjects were classified as obese if their BMI ≥ 95 th percentile. SNHL was defined as average pure-tone level greater than 15 dB for 0.5, 1, and 2 kHz (low frequency) and 3, 4, 6, and 8 kHz (high frequency).

RESULTS

Compared to normal weight participants (BMI 5%-85%), obesity in adolescents was associated with elevated pure tone hearing thresholds and greater prevalence of unilateral low-frequency SNHL (15.2 vs. 8.3%, P = 0.01). In multivariate analyses, obesity was associated with a 1.85 fold increase in the odds of unilateral low-frequency SNHL (95% CI: 1.10-3.13) after controlling for multiple hearing-related covariates.

CONCLUSIONS

We demonstrate for the first time that obesity in childhood is associated with higher hearing thresholds across all frequencies and an almost 2-fold increase in the odds of unilateral low-frequency hearing loss. These results add to the growing literature on obesity-related health disturbances and also add to the urgency in instituting public health measures to reduce it.

Healthy diets, healthy hearing: National Health and Nutrition Examination Survey, 1999-2002

OBJECTIVE

A significant relationship between dietary nutrient intake and susceptibility to acquired hearing loss is emerging. Variability in the outcomes across studies is likely related to differences in the specific metrics used to quantify nutrient intake and hearing status. Most studies have used single nutrient analysis. Although this analysis is valuable, interactions between nutrients are increasingly recognized and could modify modeling of single nutrient effects. Therefore, we examined the potential relationship between diet and hearing using a metric of overall dietary quality.

DESIGN

This cross-sectional analysis was based on healthy eating index data and audiological thresholds.

STUDY SAMPLE

Data for adults between the ages of 20 to 69 years of age were drawn from the National Health and Nutrition Examination Survey, 1999-2002.

RESULTS

Controlling for age, race/ethnicity, sex, education, diabetes, and noise exposure, we found a significant negative relationship (Wald F = 6.54, df = 4, 29; p ≤ 0.05) between dietary quality and thresholds at higher frequencies, where higher dietary quality was associated with lower hearing thresholds. There was no statistically significant relationship between dietary quality and threshold sensitivity at lower frequencies.

CONCLUSIONS

The current findings support an association between healthier eating and better high frequency thresholds in adults.

Promoting Hearing Loss Prevention in Audiology Practice

An audiologist should be the principal provider and advocate for all hearing loss prevention activities. Many audiologists equate hearing loss prevention with industrial audiology and occupational hearing conservation programs. However, an audiologist’s involvement in hearing loss prevention should not be confined to that one particular practice setting. In addition to supervising occupational programs, audiologists are uniquely qualified to raise awareness of hearing risks, organize public health campaigns, promote healthy hearing, implement intervention programs, and monitor outcomes. For example, clinical audiologists can show clients how to use inexpensive sound level meters, noise dosimeters, or phone apps to measure noise levels, and recommend appropriate hearing protection. Audiologists should identify community events that may involve hazardous exposures and propose strategies to minimize risks to hearing. Audiologists can help shape the knowledge, beliefs, motivations, attitudes, and behaviors of individuals toward self-protection. An audiologist has the education, tools, opportunity, and strategic position to facilitate or promote hearing loss surveillance and prevention services and activities. This article highlights real-world examples of the various roles and substantial contributions audiologists can make toward hearing loss prevention goals.

[Results of hearing screenings in 14- to 15-year old adolescents]

BACKGROUND

A hearing screening among 14- to 15-year-old pupils was performed to estimate the number of hearing-impaired individuals in the adolescent population.

MATERIALS AND METHODS

A total of 1,298 pupils from 30 schools in Tyrol (Austria) participated in the screening. Hearing tests were performed in a silent room at the school. Sinus tones at frequencies 0.5/1/2/4/6 kHz and at levels of 25/20/20/20/20 dB HL, respectively, were delivered via headphones to either ear. Failure of screening was defined as not hearing one or more frequencies in one or both ears.

RESULTS

The screening was failed by 16.3% of the pupils. There was a small but not significant difference between males and females (17.0 vs. 15.2%). Most of the pupils failed at only one frequency (9.6%). Failing at two or more frequencies in the same ear occurred in 3.9% of the pupils, thereof in 1.1% bilaterally.

CONCLUSION

As the specificity of our screening is limited, false-positive results may result. Thus, the rate of hearing deficits in our sample is probably a bit lower than indicated by the figures above. Most of the adolescents who failed the screen failed at only one frequency. These subjects have a small elevation of their hearing threshold, not a hearing loss in the sense of a raised averaged threshold. A hearing loss in the latter sense is supposed to be present in only very few percent of adolescents, a bilateral hearing loss in perhaps less than 1%.

Audiometric thresholds among a Canadian sample of 10 to 17 year old students

A total of 237 students, 10 to 17 years of age, from 14 schools underwent hearing evaluations. Otoscopic examination, tympanometry and air-conduction pure tone audiometry was conducted at low (0.5, 1, 2 kHz) and high (4 and 8 kHz) frequencies. In all schools, hearing thresholds were measured with headphones in a portable audiometric booth. Socio-demographic information from students and their parents were collected using questionnaires. Overall, the prevalence of any hearing loss greater than 15 dB was 22.3% for low or high frequency pure tone averages. Self-reported symptoms of hearing loss, such as tinnitus, difficulty following a conversation with background noise, and having to turn up the TV/radio more than in the past, were associated with audiometric thresholds, most notably at 4 kHz. These study findings are among the first to provide a detailed characterization of hearing status in a sample of youth in a Canadian demographic.

Noise-induced hearing threshold shift among US adults and implications for noise-induced hearing loss: National Health and Nutrition Examination Surveys

The objective of this study was to estimate the prevalence and evaluate the associated risk factors of the noise-induced hearing threshold shift (NITS) in the US adult population based on the National Health and Nutrition Examination Surveys (NHANES). The study population consisted of 5,418 individuals aged 20-69 years who had complete audiologic data from the NHANES database. Stringent criteria were used to define NITS. Prevalence of unilateral, bilateral, and total NITS and their association with several socio-demographic and hearing-related factors were evaluated. The prevalence of unilateral, bilateral, and total NITS was 9.4, 3.4 and 12.8%, respectively. Prevalence of bilateral NITS was higher in subjects with older age, male gender, white (non-Hispanic) and Hispanic ethnicities, education level less than or equal to high school diploma, married/living with partner status, Mexico as country of birth, service in armed forces, smoking history, diabetes, and different kinds of noise exposure. Odds of NITS were only higher in older people, males, and smokers. This study provides comprehensive information on the prevalence of NITS in the US adult population and its associated risk factors. More targeted interventions may be done for educational, preventative, and screening purposes.

The challenge of detecting minimal hearing loss in audiometric surveys

PURPOSE

This tutorial provides framework and context for understanding the complex interaction of hearing measurement methodology and cohort social factors, as well as their relation to approaches to data interpretation and identification of minimal hearing loss (HL) in audiometric surveys.

METHOD

Pertinent archival studies were reviewed, and an original analysis on U.S. Centers for Disease Control and Prevention (CDC) audiometric survey data from children (ages 6-19) was performed.

CONCLUSION

The definition of an otologically normal individual, the pass-fail criterion representing the upper limit of the range of normal hearing, and the quality of the audiometry affect the percentage of persons who are falsely identified as having a minimal HL. An upper limit of normal hearing of 15 dB HL yields an unacceptably high false-positive rate, particularly when the more variable higher audiometric frequencies are examined. When air-conduction thresholds are assessed in isolation to estimate potential noise damage, the failure to exclude persons who have possible middle and external ear problems, including earwax, results in high false-positive rates. When these factors and other limitations are considered, audiograms from teens from a recent CDC survey do not show evidence consistent with widespread noise-induced HL. Suggestions are made to improve the effectiveness of pure-tone audiometry and the identification of minimal HL.

Randomized trial of a hearing conservation intervention for rural students: long-term outcomes

OBJECTIVES

We had the rare opportunity to conduct a cluster-randomized controlled trial to observe the long-term (16-year) effects of a well-designed hearing conservation intervention for rural high school students. This trial assessed whether the intervention resulted in (1) reduced prevalence of noise-induced hearing loss (NIHL) assessed clinically and/or (2) sustained use of hearing protection devices.

METHODS

In 1992-1996, 34 rural Wisconsin schools were recruited and 17 were assigned randomly to receive a comprehensive, 3-year, hearing conservation intervention. In 2009-2010, extensive efforts were made to find and contact all students who completed the original trial. Participants in the 16-year follow-up study completed an exposure history questionnaire and a clinical audiometric examination. Rates of NIHL and use of hearing protection were compared.

RESULTS

We recruited 392 participants from the original trial, 200 (53%) from the intervention group and 192 (51%) from the control group. Among participants with exposure to agricultural noise, the intervention group reported significantly greater use of hearing protection compared with the control group (25.9% vs 19.6%; P = .015). The intervention group also reported significantly greater use of hearing protection for shooting guns (56.2% vs 41.6%; P = .029), but the groups reported similar uses of protection in other contexts. There was no significant difference between groups with respect to objective measures of NIHL.

CONCLUSION

This novel trial provides objective evidence that a comprehensive educational intervention by itself may be of limited effectiveness in preventing NIHL in a young rural population.

Ear diseases among secondary school students in Xi'an, China: the role of portable audio device use, insomnia and academic stress

Background

Hearing impairment negatively impacts students' development of academic, language and social skills. Even minimal unilateral hearing loss can hinder educational performance. We investigated the prevalence of ear diseases among secondary school students in the city of Xi'an, China in order to provide a foundation for evidence-based hearing healthcare.

Methods

A stratified random sampling survey was conducted in 29 secondary schools. Demographics and medical histories were collected, and otologic examinations were performed. Questionnaires were administered to assess insomnia, academic stress and use of portable audio devices. Logistic regression analysis was used to identify factors associated with hearing impairment, and the association of sensorineural hearing loss with insomnia, academic stress and the use of portable audio devices was analyzed with the chi-square test.

Results

The percentage of students with some form of ear disease was 3.32%. External ear disease, middle ear disease and sensorineural hearing loss occurred in 1.21%, 0.64% and 1.47% of the students, respectively. Boys had a relatively higher prevalence of ear disease than girls. According to our survey, the prevalence of sensorineural hearing loss increased significantly among the students with insomnia and extended use of portable audio devices, but not among those with elevated levels of academic stress. Hearing aids and surgical treatment were needed in 1.47% and 0.89% of the students, respectively.

Conclusions

There is a high prevalence of ear disease among secondary school students, and this should be given more attention. Insomnia and the excessive use of portable audio devices may be related to adolescent sensorineural hearing loss. It is important to establish and comply with an evidence-based preventive strategy.

Targeting hearing health messages for users of personal listening devices

PURPOSE

To summarize the literature on patterns and risks of personal listening device (PLD) use, which is ubiquitous among teenagers and young adults. The review emphasizes risk awareness, health concerns of PLD users, inclination to take actions to prevent hearing loss from exposure to loud music, and specific instructional messages that are likely to motivate such preventive actions.

METHOD

We conducted a systematic, critical review of the English-language scholarly literature on the topic of PLDs and their potential effects on human hearing. We used popular database search engines to locate relevant professional journals, books, recent conference papers, and other reference sources.

CONCLUSIONS

Adolescents and young adults appear to have somewhat different perspectives on risks to hearing posed by PLD use. Messages designed to suggest actions they might take in avoiding or reducing these risks, therefore, need to be targeted to achieve optimal outcomes. We offer specific recommendations regarding the framing and content of educational messages that are most likely to be effective in reducing the potentially harmful effects of loud music on hearing in these populations, and we note future research needs.