Health effects from noise

Noise health effects are the physical and psychological health consequences of regular exposure to consistent elevated sound levels. Noise from traffic, in particular, is considered by the World Health Organization to be one of the worst environmental stressors for humans, second only to air pollution.[1] Elevated workplace or environmental noise can cause hearing impairment, tinnitus, hypertension, ischemic heart disease, annoyance, and sleep disturbance.[2][3] Changes in the immune system and birth defects have been also attributed to noise exposure.[4]

An audiologist conducting an audiometric hearing test in a sound-proof testing booth

Although age-related health effects (presbycusis) occur naturally with age,[5] in many countries the cumulative impact of noise is sufficient to impair the hearing of a large fraction of the population over the course of a lifetime.[6][7] Noise exposure has been known to induce noise-induced hearing loss, tinnitus, hypertension, vasoconstriction, and other cardiovascular adverse effects.[8][9] Chronic noise exposure has been associated with sleep disturbances and increased incidence of diabetes. Adverse cardiovascular effects occur from chronic exposure to noise due to the sympathetic nervous system's inability to habituate. The sympathetic nervous system maintains lighter stages of sleep when the body is exposed to noise, which does not allow blood pressure to follow the normal rise and fall cycle of an undisturbed circadian rhythm.[2]

Stress from time spent around elevated noise levels has been linked with increased workplace accident rates and aggression and other anti-social behaviors.[10] The most significant sources are vehicles, aircraft, prolonged exposure to loud music, and industrial noise.[11]

There are approximately 10,000 deaths per year as a result of noise in the European Union.[12][13]

Noise induced hearing loss
Main article: Noise-induced hearing loss

Noise-induced hearing loss is a permanent shift in pure-tone thresholds, resulting in sensorineural hearing loss. The severity of a threshold shift is dependent on duration and severity of noise exposure. Noise-induced threshold shifts are seen as a notch on an audiogram from 3000–6000 Hz, but most often at 4000 Hz.[14]

Exposure to loud noises, either in a single traumatic experience or over time, can damage the auditory system and result in hearing loss and sometimes tinnitus as well. Traumatic noise exposure can happen at work (e.g., loud machinery), at play (e.g., loud sporting events, concerts, recreational activities), and/or by accident (e.g., a backfiring engine.) Noise induced hearing loss is sometimes unilateral and typically causes patients to lose hearing around the frequency of the triggering sound trauma.[15]

Tinnitus

Tinnitus is an auditory disorder characterized by the perception of a sound (ringing, chirping, buzzing, etc.) in the ear in the absence of an external sound source. There are two types of tinnitus: subjective and objective. Subjective is the most common and can only be heard "in the head" by the person affected. Objective tinnitus can be heard from those around the affected person and the audiologist can hear it using a stethoscope.Tinnitus can also be categorised by the way it sounds in one's ear, pulsatile tinnitus [16] which is caused by the vascular nature of Glomus tumours and non-pulsatile tinnitus which usually sounds like crickets, the sea and bees.

Though the pathophysiology of tinnitus isn't known, noise exposure can be a contributing factor, therefore tinnitus can be associated with hearing loss, generated by the cochlea and central nervous system (CNS). High frequency hearing loss causes a high pitched tinnitus and low frequency hearing loss causes a roaring tinnitus.[17] Noise-induced tinnitus can be temporary or permanent depending on the type and amount of noise a person was exposed to.

Cardiovascular effects

Noise has been associated with important cardiovascular health problems, particularly hypertension.[18][19][20] Noise levels of 50 dB(A) or greater at night may increase the risk of myocardial infarction by chronically elevating cortisol production.[21][22][23]

Traffic noise has several negative effects, including increased risk for coronary artery disease, with night-time exposure to noise possibly more harmful than day-time exposure.[1] It has also been shown to increase blood pressure in individuals within the surrounding residential areas, with railways causing the greatest cardiovascular effects.[24][25] Roadway noise levels are sufficient to constrict arterial blood flow and lead to elevated blood pressure.[26][24] Vasoconstriction can result from elevated adrenaline levels or through medical stress reactions. Long-term exposure to noise is correlated to increase in cortisol and angiotensin-II levels which are respectively associated with oxidative stress and vascular inflammation.[1] Individuals subject to great than 80 dB(A) in the workplace are at increased risk of having increased blood pressure.[27][28]

Other physical health effects

Traffic noise may also increase the risk of stroke, diabetes, and becoming overweight.[1]

Psychological impacts of noise

Causal relationships have been discovered between noise and psychological effects such as annoyance, psychiatric disorders, and effects on psychosocial well-being.[4] Exposure to intense levels of noise can cause personality changes and violent reactions.[29] Noise has also been shown to be a factor that attributed to violent reactions.[30] The psychological impacts of noise also include an addiction to loud music. This was researched in a study where non-professional musicians were found to have loudness addictions more often than non-musician control subjects.[31]

Psychological health effects from noise include depression and anxiety. Individuals who have hearing loss, including noise induced hearing loss, may have their symptoms alleviated with the use of hearing aids. Individuals who do not seek treatment for their loss are 50% more likely to have depression than their aided peers.[32] These psychological effects can lead to detriments in physical care in the form of reduced self-care, work-tolerance, and increased isolation.[33]

Auditory stimuli can serve as psychological triggers for individuals with post traumatic stress disorder (PTSD).[34]

Stress

Research commissioned by Rockwool, a multi-national insulation manufacturer headquartered in Denmark, reveals that in the UK one third (33%) of victims of domestic disturbances claim loud parties have left them unable to sleep or made them stressed in the last two years. Around one in eleven (9%) [35] of those affected by domestic disturbances claims it has left them continually disturbed and stressed. More than 1.8 million people claim noisy neighbours have made their life a misery and they cannot enjoy their own homes. The impact of noise on health is potentially a significant problem across the UK given that more than 17.5 million Britons (38%) have been disturbed by the inhabitants of neighbouring properties in the last two years. For almost one in ten (7%) Britons this is a regular occurrence.[36]

The extent of the problem of noise pollution for public health is reinforced by figures collated by Rockwool from local authority responses to a Freedom of Information Act (FOI) request. This research reveals in the period April 2008 - 2009 UK councils received 315,838 complaints about noise pollution from private residences. This resulted in environmental health officers across the UK serving 8,069 noise abatement notices, or citations under the terms of the Anti-Social Behaviour (Scotland) Act.[36]

Westminster City Council[37] has received more complaints per head of population than any other district in the UK with 9,814 grievances about noise, which equates to 42.32 complaints per thousand residents. Eight of the top 10 councils ranked by complaints per 1,000 residents were in London.

Annoyance

Sudden impulse noises are typically perceived as more bothersome than noise from traffic of equal volume.[38] Annoyance effects of noise are minimally affected by demographics, but fear of the noise source and sensitivity to noise both strongly affect the 'annoyance' of a noise.[39] Sound levels as low as 40 dB(A) can generate noise complaints[40] and the lower threshold for noise producing sleep disturbance is 45 dB(A) or lower.[41]

Other factors that affect the "annoyance level" of sound include beliefs about noise prevention and the importance of the noise source, and annoyance at the cause (i.e., non-noise related factors) of the noise.[42] Many of the interpretations of the level of annoyance and the relationship between noise levels and resulting health symptoms could be influenced by the quality of interpersonal relationships at the workplace, as well as the stress level generated by the work itself.[4][43] Evidence for impact on annoyance of long-term noise versus recent changes is equivocal.[42]

Approximately 35% to 40% of office workers find noise levels from 55 to 60 dB(A) extremely irritating.[4] The noise standard in Germany for mentally stressful tasks is set at 55 dB(A),[44] however, if the noise source is continuous, the threshold level for tolerability among office workers is lower than 55 dB(A).[4]

Child physical development

The U.S. Environmental Protection Agency authored a pamphlet in 1978 that suggested a correlation between low-birthweight (using the World Health Organization definition of less than 2,500 grams (88 oz)) and high sound levels, and also high rates of birth defects in places where expectant mothers are exposed to elevated sound levels, such as typical airport environs. Specific birth abnormalities included harelip, cleft palate, and defects in the spine.[45]

According to Lester W. Sontag of The Fels Research Institute (as presented in the same EPA study): “There is ample evidence that environment has a role in shaping the physique, behavior, and function of animals, including man, from conception and not merely from birth. The fetus is capable of perceiving sounds and responding to them by motor activity and cardiac rate change." The effects of noise exposure are highest when it occurs between 15 and 60 days after conception, a period in which major internal organs and the central nervous system are formed.[45]

Later developmental effects occur as vasoconstriction in the mother reduces blood flow and therefore oxygen and nutrition to the fetus. Low birth weights and noise were also associated with lower levels of certain hormones in the mother. These hormones are thought to affect fetal growth and to be good indicators of protein production. The difference between the hormone levels of pregnant mothers in noisy versus quiet areas increased as birth approached.[45]

In a 2000 publication, a review of studies on birthweight and noise exposure note that while some older studies suggest that when women are exposed to >65 dB aircraft noise a small decrease in birthweight occurs, in a more recent study of 200 Taiwanese women including noise dosimetry measurements of individual noise exposure, the authors found no significant association between noise exposure and birth weight after adjusting for relevant confounders, e.g. social class, maternal weight gain during pregnancy, etc.[4]

Cognitive development

When young children are regularly exposed to levels of noise that interfere with speech, they may develop speech or reading difficulties, because auditory processing functions are compromised. Children continue to develop their speech perception abilities until they reach their teens. Evidence has shown that when children learn in noisier classrooms, they have more difficulties understanding speech than those who learn in quieter settings.[46]

In a study conducted by Cornell University in 1993, children exposed to noise in learning environments experienced trouble with word discrimination, as well as various cognitive developmental delays.[47][48] In particular, the writing learning impairment dysgraphia is commonly associated with environmental stressors in the classroom.[49]

High noise levels have also been known to damage the physical health of small children. Children from noisy residences often have a heart rate that is significantly higher (by 2 beats/min on average) than those of children from quieter homes.[50]

Prevention
Main article: Hearing protection device
Different styles of earplugs are pictured. Left, pre-molded earplugs. Center, formable earplugs. Right, roll-down foam earplugs.

A hearing protection device (HPD) is an ear protection device worn in or over the ears while exposed to hazardous noise to help prevent noise-induced hearing loss. HPDs reduce (not eliminate) the level of the noise entering the ear. HPDs can also protect against other effects of noise exposure such as tinnitus and hyperacusis. Proper hygiene and care of HPDs may reduce chances of outer ear infections.[51] There are many different types of HPDs available for use, including earmuffs, earplugs, electronic hearing protection devices, and semi-insert devices.[52] One can measure the personal attenuation rating through a hearing protection fit-testing system.

Earmuff style hearing protection devices are designed to fit over the outer ear, or pinna. Earmuff HPDs typically consist of two ear cups and a head band.[52] Earplug style hearing protection devices are designed to fit in the ear canal. Earplugs come in a variety of different subtypes.[52] Some HPDs reduce the sound reaching the eardrum through a combination of electronic and structural components. Electronic HPDs are available in both earmuff and custom earplug styles. Electronic microphones, circuitry, and receivers perform active noise reduction, also known as noise-cancelling, in which a signal that is 180-degrees out-of-phase of the noise is presented, which in theory cancels the noise.[52] Canal caps are similar to earplugs in that they consists of soft tip that is inserted into the opening of the ear canal.[52]

Regulations
Main article: Noise regulation

Environmental noise regulations usually specify a maximum outdoor noise level of 60 to 65 dB(A), while occupational safety organizations recommend that the maximum exposure to noise is 40 hours per week at 85 to 90 dB(A). For every additional 3 dB(A), the maximum exposure time is reduced by a factor 2, e.g. 20 hours per week at 88 dB(A). Sometimes, a factor of two per additional 5 dB(A) is used, however, these occupational regulations are acknowledged by the health literature as inadequate to protect against hearing loss and other health effects. In an effort to prevent noise-induced hearing loss, many programs and initiative have been created, like the Buy Quiet program, which encourages employers to purchase quieter tools and equipment, and the Safe-In-Sound Award, which recognizes organizations with successful hearing loss prevention strategies.[53][54]

With regard to indoor noise pollution in residences, the U.S. Environmental Protection Agency (EPA) has not set any restrictions on limits to the level of noise. Rather, it has provided a list of recommended levels in its Model Community Noise Control Ordinance, which was published in 1975. For instance, the recommended noise level for indoor residences is less than or equal to 45 dB.[55][56]

Noise pollution control in residences is not funded by the federal government in part because of the disagreements in establishing causal links between sounds and health risks, since the effect of noise is often psychological and also, because it leaves no singular tangible trace of damage on the human body. For instance, hearing loss could be attributed to a variety of factors including age, rather than solely due to excessive exposure to noise.[57][58] A state or local government is able to regulate indoor residential noise, however, such as when excessive noise from within a home causes disturbances to nearby residences.[57][59]

Effects on dogs

While people are often educated on the effects of noise exposure in humans, there are also different noise exposure effects in animals as well. An example of this would be in dogs, and the noise exposure levels occurring within kennels. Dogs experience this noise exposure whether it be a long stay at an animal shelter, or a weekend stay at a boarding facility.

Organizations like NIOSH and OSHA have different regulations when it comes to the noise exposure levels in industrial workers. Currently there are no regulations related to the noise exposure for dogs even with such damaging effects related to their health. Health risks dogs are exposed to include ear damage and behavioral changes.

The average noise exposure in a kennel is greater than 100 dB SPL. According to OSHA these levels would yield in the use of hearing protection for the workers of those kennels due to the risk of noise induced hearing loss. The anatomical structures of the human and dog ears are very similar, so it is thought that these levels will negatively impact the hearing of canines in kennels. The ABR can be used to estimate the hearing threshold of dogs, and can be used to show either a temporary threshold shift or permanent threshold shift after being exposed to excessive sound levels.[60]

Behavioral effects to excessive noise exposure include hiding, urinating, defecating, panting, pacing, drooling, disregard to commands, trembling, and barking.[61] These behavioral patterns pose a much greater problem to canines than meets the eye. All of these behavioral patterns are characteristics that result in a longer stay at the kennels before being adopted.[62] A longer stay at the shelter results in a longer duration of noise exposure and therefore more likely to show either a temporary or permanent threshold shift in the canine's hearing.[60]

These excessive noise levels are not only harming the dogs physical and psychological state, but the workers' and potential adoptive families' physical and psychological state as well. The workers' psychological state could affect the care provided to the dogs. These loud noise exposures also have the potential to reduce the amount of time that potential adoptive families spend in the facility. This can result in less dogs being adopted and more time being exposed to excessive sound levels.[63]

To reduce the level of noise exposure poses a little more difficulty because the majority of the noise is coming from the dogs (barking), but structural changes can be made to the facilities in order to reduce the noise. Structural changes could include how many dogs are put in one area, more absorbing material rather than metal cages and cement walls and floors, and possibly in the future use of hearing protection devices (HPD) for the dogs. All of these structural changes would also benefit the humans involved as well as the use of HPD's (ear plugs).

See also

References
  1. Münzel, Thomas; Kröller-Schön, Swenja; Oelze, Matthias; Gori, Tommaso; Schmidt, Frank P.; Steven, Sebastian; Hahad, Omar; Röösli, Martin; Wunderli, Jean-Marc; Daiber, Andreas; Sørensen, Mette (2020). "Adverse Cardiovascular Effects of Traffic Noise with a Focus on Nighttime Noise and the New WHO Noise Guidelines". Annual Review of Public Health. 41: 309–328. doi:10.1146/annurev-publhealth-081519-062400. PMID 31922930.
  2. Münzel T, Schmidt FP, Steven S, Herzog J, Daiber A, Sørensen M (February 2018). "Environmental Noise and the Cardiovascular System". Journal of the American College of Cardiology. 71 (6): 688–697. doi:10.1016/j.jacc.2017.12.015. PMID 29420965.
  3. Kerns E, Masterson EA, Themann CL, Calvert GM (June 2018). "Cardiovascular conditions, hearing difficulty, and occupational noise exposure within US industries and occupations". American Journal of Industrial Medicine. 61 (6): 477–491. doi:10.1002/ajim.22833. PMC 6897488. PMID 29537072.
  4. Passchier-Vermeer W, Passchier WF (March 2000). "Noise exposure and public health". Environmental Health Perspectives. 108 Suppl 1 (Suppl 1): 123–31. doi:10.1289/ehp.00108s1123. JSTOR 3454637. PMC 1637786. PMID 10698728.
  5. Rosenhall U, Pedersen K, Svanborg A (August 1990). "Presbycusis and noise-induced hearing loss". Ear and Hearing. 11 (4): 257–63. doi:10.1097/00003446-199008000-00002. PMID 2210099.
  6. Schmid RE (2007-02-18). "Aging nation faces growing hearing loss". CBS News. Archived from the original on 2007-11-15. Retrieved 2007-02-18.
  7. Senate Public Works Committee, Noise Pollution and Abatement Act of 1972, S. Rep. No. 1160, 92nd Cong. 2nd session
  8. "Noise: Health Effects and Controls" (PDF). University of California, Berkeley. Archived from the original (PDF) on 2007-09-25. Retrieved 2007-12-22.
  9. Kerns, Ellen; Masterson, Elizabeth A.; Themann, Christa L.; Calvert, Geoffrey M. (2018). "Cardiovascular conditions, hearing difficulty, and occupational noise exposure within US industries and occupations". American Journal of Industrial Medicine. 61 (6): 477–491. doi:10.1002/ajim.22833. PMC 6897488. PMID 29537072.
  10. Kryter KD (1994). The handbook of hearing and the effects of noise: physiology, psychology, and public health. Boston: Academic Press. ISBN 978-0-12-427455-6.
  11. "10. Noise" (PDF). Natural Resources and the Environment 2006. 2006. pp. 188–189. Archived from the original (PDF) on November 14, 2011.
  12. "Noise in Europe 2014". European Environment Agency.
  13. Godwin R (3 July 2018). "Sonic doom: how noise pollution kills thousands each year". The Guardian – via www.theguardian.com.
  14. Katz J, Chasin M, English KM, Hood LJ, Tillery KL (2014-09-19). Handbook of clinical audiology (Seventh ed.). Philadelphia. ISBN 978-1-4511-9163-9. OCLC 877024342.
  15. "Causes". American Tinnitus Association. 2015-03-02. Retrieved 2019-02-22.
  16. Waldvogel D, Mattle HP, Sturzenegger M, Schroth G (March 1998). "Pulsatile tinnitus--a review of 84 patients" (PDF). Journal of Neurology. 245 (3): 137–42. doi:10.1007/s004150050193. PMID 9553842. S2CID 10767191.
  17. Nicolas-Puel C, Faulconbridge RL, Guitton M, Puel JL, Mondain M, Uziel A (2002). "Characteristics of tinnitus and etiology of associated hearing loss: a study of 123 patients". The International Tinnitus Journal. 8 (1): 37–44. PMID 14763234.
  18. Ising H, Babisch W, Kruppa B (1999). "Noise-Induced Endocrine Effects and Cardiovascular Risk". Noise & Health. 1 (4): 37–48. PMID 12689488.
  19. Davies H, Kamp IV (2012-11-01). "Noise and cardiovascular disease: a review of the literature 2008-2011". Noise & Health. 14 (61): 287–91. doi:10.4103/1463-1741.104895. PMID 23257579.
  20. Lin FR, Metter EJ, O'Brien RJ, Resnick SM, Zonderman AB, Ferrucci L (February 2011). "Hearing loss and incident dementia". Archives of Neurology. 68 (2): 214–20. doi:10.1001/archneurol.2010.362. PMC 3277836. PMID 21320988.
  21. Maschke C (2003). "Stress Hormone Changes in Persons exposed to Simulated Night Noise". Noise & Health. 5 (17): 35–45. PMID 12537833.
  22. Franssen EA, van Wiechen CM, Nagelkerke NJ, Lebret E (May 2004). "Aircraft noise around a large international airport and its impact on general health and medication use". Occupational and Environmental Medicine. 61 (5): 405–13. doi:10.1136/oem.2002.005488. PMC 1740783. PMID 15090660.
  23. Lercher P, Hörtnagl J, Kofler WW (1993). "Work noise annoyance and blood pressure: combined effects with stressful working conditions". International Archives of Occupational and Environmental Health. 65 (1): 23–8. doi:10.1007/BF00586054. PMID 8354571. S2CID 41612151.
  24. Lee PJ, Park SH, Jeong JH, Choung T, Kim KY (November 2019). "Association between transportation noise and blood pressure in adults living in multi-storey residential buildings". Environment International. 132: 105101. doi:10.1016/j.envint.2019.105101. PMID 31434052.
  25. Dzhambov A, Tilov B, Markevych I, Dimitrova D (December 2017). "Residential road traffic noise and general mental health in youth: The role of noise annoyance, neighborhood restorative quality, physical activity, and social cohesion as potential mediators". Environment International. 109: 1–9. doi:10.1016/j.envint.2017.09.009. PMID 28917129.
  26. Klompmaker JO, Janssen NA, Bloemsma LD, Gehring U, Wijga AH, van den Brink C, et al. (August 2019). "Associations of Combined Exposures to Surrounding Green, Air Pollution, and Road Traffic Noise with Cardiometabolic Diseases". Environmental Health Perspectives. 127 (8): 87003. doi:10.1289/EHP3857. PMC 6792364. PMID 31393793.
  27. Chang TY, Liu CS, Huang KH, Chen RY, Lai JS, Bao BY (April 2011). "High-frequency hearing loss, occupational noise exposure and hypertension: a cross-sectional study in male workers". Environmental Health. 10: 35. doi:10.1186/1476-069X-10-35. PMC 3090324. PMID 21518430.
  28. Chang TY, Su TC, Lin SY, Jain RM, Chan CC (November 2007). "Effects of occupational noise exposure on 24-hour ambulatory vascular properties in male workers". Environmental Health Perspectives. 115 (11): 1660–4. doi:10.1289/ehp.10346. PMC 2072860. PMID 18008000.
  29. "Children and Noise" (PDF). World Health Organization.
  30. Elizondo-Garza FJ (1999). "Noise problems, savage approaches. From just forget it, to physical violence". The Journal of the Acoustical Society of America. 105 (2): 942. Bibcode:1999ASAJ..105..942E. doi:10.1121/1.425711.
  31. Schmuziger N, Patscheke J, Stieglitz R, Probst R (January 2012). "Is there addiction to loud music? Findings in a group of non-professional pop/rock musicians". Audiology Research. 2 (1): e11. doi:10.4081/audiores.2012.e11. PMC 4630946. PMID 26557326.
  32. "Silently Suffering From Hearing Loss Negatively Affects Quality of Life". American Psychological Association. Retrieved 2018-03-01.
  33. Hammer MS, Swinburn TK, Neitzel RL (February 2014). "Environmental noise pollution in the United States: developing an effective public health response". Environmental Health Perspectives. 122 (2): 115–9. doi:10.1289/ehp.1307272. PMC 3915267. PMID 24311120.
  34. Glad KA, Hafstad GS, Jensen TK, Dyb G (August 2017). "A longitudinal study of psychological distress and exposure to trauma reminders after terrorism". Psychological Trauma: Theory, Research, Practice, and Policy. 9 (Suppl 1): 145–152. doi:10.1037/tra0000224. PMID 27831737. S2CID 24474520.
  35. "How Noisy Neighbours Blight Millions of Lives". The Daily Express.
  36. Clout L (2009-04-08). "How noisy neighbours millions of lives". Express.co.uk.
  37. "London is home to the noisiest neighbours". The Evening Standard. Archived from the original on 2013-01-14.
  38. Miedema and Oudshoorn 2001 cited in "Hypertension and exposure to noise near airports". Medscape.
  39. Miedema HM, Vos H (1999). "Demographic and attitudinal factors that modify annoyance from transportation noise". Journal of the Acoustical Society of America. 105 (6): 3336–44. Bibcode:1999ASAJ..105.3336M. doi:10.1121/1.424662.
  40. Gelfand SA (2001). Essentials of Audiology. New York: Thieme Medical Publishers. ISBN 978-1-58890-017-3.
  41. Walker JR, Fahy F (1998). Fundamentals of noise and vibration. London: E & FN Spon. ISBN 978-0-419-22700-7.
  42. Field JM (1993). "Effect of personal and situational variables upon noise annoyance in residential areas". Journal of the Acoustical Society of America. 93 (5): 2753–63. Bibcode:1993ASAJ...93.2753F. doi:10.1121/1.405851.
  43. Halpern D (1995). Mental health and the built environment: more than bricks and mortar?. Taylor & Francis. ISBN 978-0-7484-0235-9.
  44. Stellman JM (1998). Encyclopedia of occupational health and safety. International Labour Organization. ISBN 978-92-2-109203-2.
  45. Noise: A Health Problem United States Environmental Protection Agency, Office of Noise Abatement and Control, Washington, D.C. 20460, August, 1978
  46. Nelson PB (1959). "Sound in the Classroom". ASHRAE Journal. 45 (2): 22–25.
  47. Evans GW, Lepore SJ (1993). "Nonauditory Effects of Noise on Children: A Critical Review". Children's Environments. 10 (1): 31–51. JSTOR 41515250.
  48. Wakefield J (June 2002). "Learning the hard way: the poor environment of America's schools". Environmental Health Perspectives. 110 (6): A298-305. doi:10.1289/ehp.110-a298. PMC 1240882. PMID 12055059.
  49. "Dysgraphiastaff". Brain.HE. Retrieved 2017-09-09.
  50. Belojevic G, Jakovljevic B, Stojanov V, Paunovic K, Ilic J (February 2008). "Urban road-traffic noise and blood pressure and heart rate in preschool children". Environment International. 34 (2): 226–31. doi:10.1016/j.envint.2007.08.003. PMID 17869340.
  51. Ntlhakana L, Kanji A and Khoza-Shangase K. (2015). "The use of hearing protection devices in South Africa: exploring the current status in a gold and a non-ferrous mine". Occupational Health Southern Africa: 10–15.
  52. Rawool VW (2011). "Chapter 6: Hearing Protection and Enhancement Devices". Hearing Conservation: In Occupational, Recreational, Educational, and Home Settings. Thieme. pp. 136–173. ISBN 978-1604062571.
  53. "CDC - Buy Quiet - NIOSH Workplace Safety and Health Topics". cdc.gov. 2019-01-10.
  54. "Safe-in-Sound: Excellence in Hearing Loss Prevention Award". Safe-in-Sound. Retrieved July 12, 2016.
  55. Williams LK, Langley RL (2000). Environmental Health Secrets. Philadelphia: Elsevier Health Sciences. ISBN 978-1-56053-408-2.
  56. "EPA Identifies Noise Levels Affecting Health and Welfare". April 2, 1972.
  57. Schmidt CW (January 2005). "Noise that annoys: regulating unwanted sound". Environmental Health Perspectives. 113 (1): A42-5. doi:10.1289/ehp.113-a42. PMC 1253730. PMID 15631959.
  58. Staples SL (February 1996). "Human response to environmental noise. Psychological research and public policy". The American Psychologist. 51 (2): 143–50. doi:10.1037/0003-066X.51.2.143. PMID 8746149.
  59. Leighton P (April 14, 2009). "Beverly considers rules to quiet loud parties". The Salem News. Archived from the original on July 16, 2012.
  60. Scheifele P, Martin D, Clark JG, Kemper D, Wells J (April 2012). "Effect of kennel noise on hearing in dogs". American Journal of Veterinary Research. 73 (4): 482–9. doi:10.2460/ajvr.73.4.482. PMID 22452494.
  61. "Noise Phobia in Dog". Veterinary World. 1.
  62. Protopopova A, Mehrkam LR, Boggess MM, Wynne CD (2014). "In-kennel behavior predicts length of stay in shelter dogs". PLOS ONE. 9 (12): e114319. Bibcode:2014PLoSO...9k4319P. doi:10.1371/journal.pone.0114319. PMC 4281133. PMID 25551460.
  63. Coppola CL, Enns RM, Grandin T (2006-01-01). "Noise in the animal shelter environment: building design and the effects of daily noise exposure". Journal of Applied Animal Welfare Science. 9 (1): 1–7. doi:10.1207/s15327604jaws0901_1. hdl:10217/4405. PMID 16649947. S2CID 12174466.


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