Vital Signs

Noise-Induced Hearing Loss Among Adults — United States 2011–2012

Yulia I Carroll, MD, PhD; John Eichwald, MA; Franco Scinicariello, MD; Howard J. Hoffman, MA; Scott Deitchman, MD; Marilyn S. Radke, MD; Christa L. Themann, MA; Patrick Breysse, PhD

Disclosures

Morbidity and Mortality Weekly Report. 2017;66(5):139-144.

Conclusions and Comments

Noise-induced hearing loss is a significant health problem among U.S. adults, is more prevalent among males, and increases with age. Persons with auditory damage caused by noise frequently do not recognize it; one in four U.S. adults who reported excellent or good hearing had an audiometric notch. Among persons who reported work exposure to loud noise, one third had a bilateral or unilateral notch.

Noise exposure is the second most common cause of acquired hearing loss (after aging).^[8] An estimated 24% of hearing loss in the United States has been attributed to workplace exposures.^[9] Noise exposure is associated with numerous adverse health effects, and reducing noise exposure is likely to improve health. A recent study suggested that reducing environmental noise exposure might save lives by decreasing the prevalence of cardiovascular heart disease.^[10] Avoiding exposure to loud environments and effective use of personal hearing protection devices (earplugs or earmuffs) have been shown to prevent hearing loss.^[3] Evidence also exists that stronger occupational regulation leads to decreased noise levels.^[11] Persons who already have impaired hearing from noise exposure can benefit from clinical rehabilitation, such as amplification through hearing aids, learning to read lips, and other compensation strategies.^[2] Use of technology, such as smart phone apps to measure sound level, provides new ways of informing decisions and actions.^§

Noise reduction and avoidance can prevent hearing loss or slow its progression. This can be accomplished by avoiding high volumes on personal listening devices; reducing listening time to high volumes of music; taking breaks from exposure; requesting lower volumes in public settings (restaurants, movie theaters); using quieter products (e.g., household appliances, power tools, recreational vehicles); reducing equipment noise by replacing worn or unbalanced machine parts; moving as far as possible from the loudest sound-producing source, such as loudspeakers or cannons at college stadiums; and using hearing protection devices.^[2,3] Hearing protectors need to fit well to reduce noise exposure effectively.

Noise exposure at younger ages needs particular attention. Damage to hearing accumulates over time so that hazardous exposure that begins earlier in life has the potential to be more damaging as persons age. The high prevalence of audiometric notches (one in five) among persons aged 20–29 years suggests that early life interventions need to be developed.

Hearing screenings can help reduce delays in diagnosis and improve access to hearing aids for those with hearing loss, thus improving health-related quality of life,^[12] yet a 2014 report found that only 46.0% of adults who had any trouble hearing had seen a health care professional about their hearing in the past 5 years.^[5] Hearing loss often progresses for years before being self-perceived or diagnosed.^[13,14] Talking to one's personal health care provider about hearing loss symptoms, tests, and ways to protect hearing, might support early diagnosis and access to hearing rehabilitation if needed.

During routine exams, primary care providers can examine patients' hearing; ask about patients' hearing and noise exposures and inform them about the benefits of hearing protection; monitor patients with hearing loss symptoms, recommend or provide hearing tests when indicated; and counsel patients with hearing loss.^[2,8,15] Studies indicate, however, that 40%–77% of primary care providers have not asked about or screened for hearing loss.^[16,17] Patients reporting hearing-related symptoms^[15] or risk factors such as noise exposure need to be referred for objective hearing assessment.^¶,** Although there is currently a lack of data to support the benefits of regular hearing screening in adults aged >50 years, the American Speech-Language-Hearing Association^†† recommends that adults be screened at least every decade through age 50 years and every 3 years thereafter. Healthy People 2020 ^§§ includes objectives to increase the proportion of adults who have had a hearing examination in the past 5 years and to increase the number referred by their health care provider for hearing evaluation and treatment.

Although there are no federal regulations regarding exposure to nonoccupational noise, a 1974 Environmental Protections Agency report^¶¶ identified 70 dB over 24 hours (75 dB over 8 hours) as the average exposure limit for intermittent environmental noise. World Health Organization (WHO) 1999 Guidelines for Community Noise*** recommend avoiding noise exposure levels that exceed 70 dB(A)^††† over a 24-hour period or 85 dB(A) over a 1-hour period. CDC's National Institute for Occupational Safety and Health (NIOSH) has established an 8-hour, time-weighted average 85 dB(A) recommended exposure limit to protect most workers from developing hearing loss from noise exposure over a 40-year career. However, at that sound pressure level [85 dB(A) time-weighted average], approximately 8% of workers could still develop hearing loss, and thus NIOSH recommends that hearing protection be worn whenever noise levels exceed 85 dB(A), regardless of the length of exposure.

The U.S. Department of Health and Human Services (DHHS) and WHO are raising awareness about noise-induced hearing loss. DHHS is collecting data on hearing status and risk factors, as well as developing guidelines on hearing aids. WHO is developing guidelines on noise exposure. Other public entities, such as states and counties, partner with community groups to reduce noisy environments and use evidence to inform policies that decrease noise exposures. Other ways to reduce environmental noise exposure include using sound-absorbent materials in office buildings and public venues, erecting highway barriers, and passing noise ordinances. Managers and owners of public venues can decrease the loudest sound levels at those locations to help decrease noise exposure.

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^§ https://blogs.cdc.gov/niosh-science-blog/2014/04/09/sound-apps/.
^¶U.S. Preventive Services Task Force. Report no. 11-05153-EF-1. Hearing loss in older adults: screening. https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/hearing-loss-in-older-adults-screening.
**NIOSH. Criteria for a recommended standard — occupational noise exposure: revised criteria. Publication No. 98–126. https://www.cdc.gov/niosh/docs/98-126/pdfs/98-126a.pdf.
^†† http://www.asha.org/uploadedFiles/aud/InfoSeriesAudScreen.pdf.
^§§ https://www.healthypeople.gov/2020/topics-objectives/topic/physical-activity/objectives?topicId=33.
^¶¶ https://nepis.epa.gov/Exe/ZyPDF.cgi/2000L3LN.PDF?Dockey=2000L3LN.PDF.
***http://www.euro.who.int/en/health-topics/environment-and-health/noise/publications.
^†††dBA indicates A-weighted decibels, an expression of the relative loudness of sounds in air as perceived by the human ear. In the A-weighted system, the decibel values of sounds at low frequencies are reduced, compared with unweighted decibels, in which no correction is made for audio frequency.

Table 1. Percentages of adults aged 20–69 years with an audiometric notch* in one ear (unilateral notch) or both ears (bilateral notch), by selected characteristics — National Health and Nutrition Examination Survey, United States, 2011–2012
Characteristic (No.)	Bilateral or unilateral notch		Bilateral notch		Unilateral notch
Characteristic (No.)	% (SE)	OR (95% CI)	% (SE)	OR (95% CI)	% (SE)	OR (95% CI)
Overall (3,583)	24.4 (1.73)	—	6.2 (0.57)	—	18.2 (1.32)	—
Sex
Male (1,841)	31.6 (1.89)	Referent	8.6 (0.76)	Referent	23.0 (1.53)	Referent
Female (1,742)	17.0 (1.90)	0.44 (0.35–0.56)	3.7 (0.95)	0.35 (0.19–0.66)	13.3 (1.23)	0.48 (0.40–0.57)
Age group (yrs)
20–29 (803)	19.2 (2.34)	Referent	4.2 (1.31)	Referent	14.9 (1.95)	Referent
30–39 (721)	24.9 (2.95)	1.40 (0.98–2.00)	4.6 (0.84)	1.16 (0.50– 2.67)	20.4 (2.65)	1.47 (0.99–2.17)
40–49 (682)	29.0 (2.86)	1.72 (1.28–2.31)	7.70 (1.31)	2.07 (1.05–4.09)	21.3 (2.21)	1.62 (1.22–2.16)
50–59 (715)	27.3 (2.05)	1.58 (1.04–2.42)	8.7 (1.56)	2.27 (0.92–5.56)	18.7 (2.21)	1.39 (0.86–2.24)
60–69 (662)	20.6 (2.99)	1.09 (0.66–1.82)	5.3 (0.91)	1.28 (0.52–3.16)	15.3 (2.76)	1.04 (0.59–1.85)
Race/Ethnicity
White, non-Hispanic (1,240)	24.0 (2.08)	Referent	6.5 (0.67)	Referent	17.6 (0.67)	Referent
Black, non-Hispanic (996)	21.1 (1.54)	0.85 (0.64–1.13)	3.6 (0.47)	0.54 (0.35–0.82)	17.5 (1.62)	0.96 (0.72–1.28)
Mexican American (381)	31.8 (3.12)	1.48 (1.06–2.05)	11.1 (2.63)	1.93 (1.09–3.42)	20.6 (2.21)	1.31 (0.94–1.83)
Education
Less than high school (690)	29.7 (3.91)	1.49 (1.00–2.21)	8.1 (2.09)	1.75 (0.89–3.42)	21.6 (3.24)	1.41 (0.92–2.15)
Completed high school (737)	28.4 (2.87)	1.40 (1.10–1.77)	8.4 (0.86)	1.78 (1.26–2.51)	20.0 (2.43)	1.28 (0.98–1.68)
More than high school (2,156)	22.1 (1.63)	Referent	5.1 (0.60)	Referent	17.0 (1.24)	Referent
Poverty income ratio
≤1 (848)	22.9 (1.81)	1.17 (0.87–1.58)	5.3 (0.80)	0.90 (0.49–1.62)	17.6 (1.62)	1.29 (0.92–1.80)
>1 to <5 (1,876)	27.0 (2.02)	1.46 (1.13–1.89)	6.7 (1.01)	1.20 (0.65–2.23)	20.3 (1.31)	1.57 (1.14–2.17)
≥5 (607)	20.2 (1.94)	Referent	6.1 (1.19)	Referent	14.1 (1.98)	Referent
Self-reported work exposure to noise^†
No (2,360)	19.9 (2.04)	Referent	5.1 (0.73)	Referent	14.8 (1.53)	Referent
Yes (1,223)	32.6 (2.48)	1.95 (1.40–2.72)	8.2 (1.09)	1.91 (1.17–3.11)	24.4 (2.20)	1.96 (1.37–2.81)
Self-reported hearing status^§
Excellent or good (2,953)	23.5 (1.92)	Referent	5.5 (0.63)	Referent	18.0 (1.57)	Referent
Little, moderate, or a lot of trouble hearing (626)	28.3 (2.99)	1.29 (0.91–1.82)	9.0 (1.53)	1.73 (1.07– 2.78)	19.4 (2.66)	1.15 (0.74–1.79)

Abbreviations: CI = confidence interval; dB = decibel; OR = odds ratio; SE = standard error.
*An audiometric notch is a deterioration in the hearing threshold (the softest sound a person can hear). An audiometric notch is present when one or more of the thresholds at 3–4, or 6 kHz exceeds the pure-tone average of the 0.5 and1 kHz thresholds by 15 dB hearing level (HL) or more, and the 8 kHz threshold is at least 5 dB HL lower (better) than the highest threshold in the 3–6 kHz range. Audiograms were not accepted if the test and retest results were greater of 10 dB. The average 1-kHz frequency was the value used in this study. Participants were excluded if they had partial audio exam, ear compliance ≤0.2mL or pressure more negative than -150 dekapascals (daPa) (normal air pressure is approximately equal on both sides of the tympanic membrane [zero daPa]).
^†Persons with no work exposure to noise included both those who reported off-work exposure to noise (e.g. noise from power tools, lawn mowers, farm machinery, cars, trucks, motorcycles, motor boats or music for 10 or more hours a week) and those who did not report exposure to off-work noise. Persons with work exposure to noise reported exposure to loud or very loud noise at work.
^§Participants were asked: "Which statement best describes your hearing (without a hearing aid)? Would you say your hearing is excellent, good, that you have a little trouble, moderate trouble, a lot of trouble, or are you deaf?"

Table 2. Percentages of adults aged 20–69 years with an audiometric notch* in one ear (unilateral notch) or both ears (bilateral notch), by reported work exposure to noise status, ^† and selected characteristics — National Health and Nutrition Examination Survey, United States, 2011–2012
Characteristic	No reported work exposure to noise (n = 2,360)				Work exposure to noise (n = 1,223)
	Bilateral or unilateral notch		Bilateral notch	Unilateral notch	Bilateral or unilateral notch		Bilateral notch	Unilateral notch
	% (SE)	OR (95% CI)	% (SE)	% (SE)	% (SE)	OR (95% CI)	% (SE)	% (SE)
Overall	19.9 (2.04)	—	5.1 (0.73)	14.8 (1.53)	32.6 (2.48)	—	8.2 (1.09)	24.44 (2.20)
Sex
Male	24.7 (2.61)	Referent	7.2 (1.22)	17.6 (2.20)	39.1 (2.24)	Referent	10.2 (1.24)	28.9 (2.18)
Female	16.6 (2.17)	0.61 (0.44–0.83)	3.7 (0.89)^§	12.9 (1.53)^§	18.3 (3.65)	0.35 (0.22–0.55)	3.7 (1.99)^§	14.6 (3.52)^§
Age group (yrs)
20–29	17.6 (2.91)	Referent	3.6 (1.69)	14.0 (1.78)	22.9 (5.07)	Referent	5.7 (2.21)	17.2 (4.67)^§
30–39	18.6 (2.82)	1.07 (0.65–1.77)	3.4 (0.94)	15.2 (2.47)	37.3 (4.97)	2.00 (1.15–3.47)	6.9 (1.34)	30.4 (4.91)^§
40–49	25.0 (3.74)	1.56 (0.91–2.68)	7.9 (1.95)	17.1 (3.05)	36.0 (3.46)	1.90 (1.05–3.43)	7.4 (2.37)	28.7 (1.66)
50–59	20.3 (3.04)	1.19 (0.73–1.95)	6.1 (1.43)	14.2 (2.46)	35.8 (2.73)	1.88 (1.01–3.50)	11.8 (2.60)	24.0 (2.87)
60–69	17.7 (3.06)	1.01 (0.59–1.72)	4.5 (1.12)	13.2 (2.91)	27.3 (5.23)	1.26 (0.60–2.66)	7.34 (1.57)	19.92 (5.37)
Race/Ethnicity
White, non-Hispanic	19.4 (2.85)	Referent	5.1 (0.95)	14.3 (2.19)	31.9 (2.60)	Referent	8.7 (1.50)	23.2 (2.24)
Black, non-Hispanic	17.7 (1.47)	0.89 (0.58–1.38)	3.3 (0.56)	14.4 (1.40)	28.6 (2.62)	0.86 (0.64–1.14)	4.2 (1.14)^§	24.4 (2.79)
Mexican American	24.2 (3.86)	1.39 (0.85–2.29)	8.7 (2.81)	14.8 (1.53)	43.0 (4.45)	1.61 (1.16–2.28)	14.8 (3.16)^§	28.2 (3.58)^§
Education
Less than high school	22.0 (2.78)	1.17 (0.81–1.69)	8.2 (1.80)^§	13.8 (2.41)	37.6 (6.52)	1.50 (0.89–2.53)	8.0 (3.26)	29.5 (5.43)
Completed high school	20.7 (3.70)	1.08 (0.73–1.61)	5.7 (1.65)	15.0 (2.87)	37.6 (4.06)	1.50 (0.98–2.32)	11.6 (2.42)§	26.0 (3.01)
More than high school	19.4 (2.07)	Referent	4.5 (0.85	14.9 (1.62)	28.6 (2.45)	Referent	6.7 (1.01)	21.9 (2.24)
Poverty income ratio
≤1	21.2 (1.76)	1.27 (0.94–1.72)	4.2 (0.78)	17.0 (1.56)	25.9 (3.24)	0.81 (0.33–1.99)	7.3 (1.60)	18.5 (3.22)
>1 to <5	20.8 (3.04)	1.24 (0.93–1.65)	5.2 (1.18)	15.6 (2.29)	35.8 (2.65)	1.30 (0.61– 2.77)	8.8 (2.05)	27.0 (2.23)
≥5	17.5 (1.64)	Referent	5.7 (1.27)	11.8 (1.80)	30.1 (7.64)	Referent	7.7 (3.41)	22.4 (7.87)
Self-reported hearing status^¶
Excellent or good	20.1 (2.25)	Referent	5.0 (0.77)	15.0 (1.68)	31.0 (3.24)	Referent	6.6 (1.22)	24.4 (2.99)
Little, moderate, or lot of trouble	18.9 (3.94)	0.93 (0.51–1.69)	5.4 (2.26)	13.4 (3.10)	36.8 (2.36)	1.30 (0.93–1.81)	12.1 (2.01)^§	24.7 (2.69)

Abbreviations: CI = confidence interval; dB = decibel; OR = odds ratio; SE = standard error.
*An audiometric notch is a deterioration in the hearing threshold (the softest sound a person can hear). An audiometric notch is present when one or more of the thresholds at 3, 4, or 6 kHz exceeds the pure-tone average of the 0.5 and1 kHz thresholds by ≥15 dB hearing level (HL), and the 8 kHz threshold is at least 5 dB HL lower (better) than the highest threshold in the 3–6 kHz range. Audiograms were not accepted if the test and retest results were greater of 10 dB. The average 1-kHz frequency was the value used in this study. Participants were excluded if they had partial audio exam, ear compliance ≤0.2mL or pressure more negative than -150 dekapascals (daPa) (normal air pressure is approximately equal on both sides of the tympanic membrane [zero daPa]).
^†Persons with no work exposure to noise included both those who reported off-work exposure to noise (e.g. noise from power tools, lawn mowers, farm machinery, cars, trucks, motorcycles, motor boats or music for 10 or more hours a week) and those who did not report exposure to off-work noise. Persons with work exposure to noise reported exposure to loud or very loud noise at work.
^§Statistical difference at p<0.5 compared with the referent group.
^¶Participants were asked: "Which statement best describes your hearing (without a hearing aid)? Would you say your hearing is excellent, good, that you have a little trouble, moderate trouble, a lot of trouble, or are you deaf?"