Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2020 Jan 27;1(1):CD010333.
doi: 10.1002/14651858.CD010333.pub3.

Sound reduction management in the neonatal intensive care unit for preterm or very low birth weight infants

Abdulraoof Almadhoob  1 , Arne Ohlsson  2
Affiliations
Meta-Analysis

Sound reduction management in the neonatal intensive care unit for preterm or very low birth weight infants

Abdulraoof Almadhoob et al. Cochrane Database Syst Rev. .

Update in

Abstract

Background: Infants in the neonatal intensive care unit (NICU) are subjected to stress, including sound of high intensity. The sound environment in the NICU is louder than most home or office environments and contains disturbing noises of short duration and at irregular intervals. There are competing auditory signals that frequently challenge preterm infants, staff and parents. The sound levels in NICUs often exceed the maximum acceptable level of 45 decibels (dB), recommended by the American Academy of Pediatrics. Hearing impairment is diagnosed in 2% to 10% of preterm infants versus 0.1% of the general paediatric population. Noise may cause apnoea, hypoxaemia, alternation in oxygen saturation, and increased oxygen consumption secondary to elevated heart and respiratory rates and may, therefore, decrease the amount of calories available for growth. Elevated levels of speech are needed to overcome the noisy environment in the NICU, thereby increasing the negative impacts on staff, newborns, and their families. High noise levels are associated with an increased rate of errors and accidents, leading to decreased performance among staff. The aim of interventions included in this review is to reduce sound levels to 45 dB or less. This can be achieved by lowering the sound levels in an entire unit, treating the infant in a section of a NICU, in a 'private' room, or in incubators in which the sound levels are controlled, or reducing the sound levels that reaches the individual infant by using earmuffs or earplugs. By lowering the sound levels that reach the neonate, the resulting stress on the cardiovascular, respiratory, neurological, and endocrine systems can be diminished, thereby promoting growth and reducing adverse neonatal outcomes.

Objectives: Primary objective To determine the effects of sound reduction on growth and long-term neurodevelopmental outcomes of neonates. Secondary objectives 1. To evaluate the effects of sound reduction on short-term medical outcomes (bronchopulmonary dysplasia, intraventricular haemorrhage, periventricular leukomalacia, retinopathy of prematurity). 2. To evaluate the effects of sound reduction on sleep patterns at three months of age. 3. To evaluate the effects of sound reduction on staff performance. 4. To evaluate the effects of sound reduction in the neonatal intensive care unit (NICU) on parents' satisfaction with the care.

Search methods: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, CINAHL, abstracts from scientific meetings, clinical trials registries (clinicaltrials.gov; controlled-trials.com; and who.int/ictrp), Pediatric Academic Societies Annual meetings 2000 to 2014 (Abstracts2ViewTM), reference lists of identified trials, and reviews to November 2014.

Selection criteria: Preterm infants (< 32 weeks' postmenstrual age (PMA) or < 1500 g birth weight) cared for in the resuscitation area, during transport, or once admitted to a NICU or a stepdown unit.

Data collection and analysis: We performed data collection and analyses according to the Cochrane Neonatal Review Group.

Main results: One small, high quality study assessing the effects of silicone earplugs versus no earplugs qualified for inclusion. The original inclusion criteria in our protocol stipulated an age of < 48 hours at the time of initiating sound reduction. We made a deviation from our protocol and included this study in which some infants would have been > 48 hours old. There was no significant difference in weight at 34 weeks postmenstrual age (PMA): mean difference (MD) 111 g (95% confidence interval (CI) -151 to 374 g) (n = 23). There was no significant difference in weight at 18 to 22 months corrected age between the groups: MD 0.31 kg, 95% CI -1.53 to 2.16 kg (n = 14). There was a significant difference in Mental Developmental Index (Bayley II) favouring the silicone earplugs group at 18 to 22 months corrected age: MD 14.00, 95% CI 3.13 to 24.87 (n = 12), but not for Psychomotor Development Index (Bayley II) at 18 to 22 months corrected age: MD -2.16, 95% CI -18.44 to 14.12 (n =12).

Authors' conclusions: To date, only 34 infants have been enrolled in a randomised controlled trial (RCT) testing the effectiveness of reducing sound levels that reach the infants' ears in the NICU. Based on the small sample size of this single trial, we cannot make any recommendations for clinical practice. Larger, well designed, conducted and reported trials are needed.

PubMed Disclaimer

Conflict of interest statement

Dr. Abdulraoof Almadhoob has no conflict of interest to report.

Dr. Arne Ohlsson has no conflict of interest to report.

Figures

1
1
Forest plot of comparison: 1 Silicone earplugs versus no earplugs, outcome: 1.1 Weight (g) at 34 weeks postmenstrual age.
2
2
Forest plot of comparison: 1 Silicone earplugs versus no earplugs, outcome: 1.6 Mental Developmental Index (Bayley II) at 18 to 22 months corrected age.
3
3
Forest plot of comparison: 1 Silicone earplugs versus no earplugs, outcome: 1.10 Passed auditory brainstem response test while in hospital.
1.1
1.1. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 1 Weight (g) at 34 weeks postmenstrual age.
1.2
1.2. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 2 Weight (kg) at 18 to 22 months corrected age.
1.3
1.3. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 3 Height at 18 to 22 months corrected age.
1.4
1.4. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 4 Fronto‐occipital circumference (cm).
1.5
1.5. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 5 Cerebral palsy at 18 to 22 months corrected age.
1.6
1.6. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 6 Mental Developmental Index (Bayley II) at 18 to 22 months corrected age.
1.7
1.7. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 7 Psychomotor Development Index (Bayley II) at 18 to 22 months corrected age.
1.8
1.8. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 8 Length of stay (days).
1.9
1.9. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 9 Days of assisted ventilation.
1.10
1.10. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 10 Passed auditory brainstem response test while in hospital.
1.11
1.11. Analysis
Comparison 1 Silicone earplugs versus no earplugs, Outcome 11 All‐cause mortality during hospital stay.
See this image and copyright information in PMC

Update of

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

References to studies included in this review

Abou Turk 2009 {published data only}
    1. Abou Turk CA, Williams AL, Lasky RE. A randomized clinical trial evaluating silicone earplugs for very low birth weight newborns in intensive care. Journal of Perinatology 2009;29(5):358‐63. - PMC - PubMed

References to studies excluded from this review

Abdeyazdan 2014 {published data only}
    1. Abdeyazdan Z, Ghassemi S, Marofi M. The effects of earmuff on physiologic and motor responses in premature infants admitted in neonatal intensive care unit. Iranian Journal of Nursing and Midwifery Research 2014;19(2):107‐12. [PUBMED: 24834077] - PMC - PubMed
Aita 2013 {published data only}
    1. Aita M, Johnston C, Goulet C, Overlander TF, Snider L. Intervention minimizing preterm infants' exposure to NICU light and noise. Clinical Nursing Research 2013;22(3):337‐58. [PUBMED: 23275433] - PubMed
Li 2009 {published data only}
    1. Li WG, Jiang HB, Gan T, Zhou WX, Chen M. The effect of noise on the auditory system and the intelligence development of premature infants treated in the neonatal intensive care unit. Zhongguo Dang Dai Er Ke Za Zhi 2009;11(12):976‐9. - PubMed
Mann 1986 {published data only}
    1. Mann NP, Haddow R, Stokes L, Goodley S, Rutter N. Effect of night and day on preterm infants in a newborn nursery: randomised trial. British Medical Journal 1986;293(6557):1265‐7. - PMC - PubMed
Zahr 1995 {published data only}
    1. Zahr LK, Traversay J. Premature infant responses to noise reduction by earmuffs: effects on behavioral and physiologic measures. Journal of Perinatology 1995;15(6):448‐55. - PubMed

Additional references

AAP 1997
    1. American Academy of Pediatrics (AAP). Committee on Environmental Health. Noise: a hazard for the fetus and newborn. Pediatrics 1997;100(4):724‐7. - PubMed
Abrams 2000
    1. Abrams RM, Gerhardt KJ. The acoustic environment and physiological responses of the fetus. Journal of Perinatology 2000;20(8 Pt 2):S30‐6. - PubMed
Anagnostakis 1980
    1. Anagnostakis D, Petmezakis J, Messaritakis J, Matsaniotis N. Noise pollution in neonatal units: a potential health hazard. Acta Paediatrica Scandinavica 1980;69(6):771‐3. - PubMed
Anagnostakis 1982
    1. Anagnostakis D, Petmezakis J, Papazissis G, Messaritakis J, Matsaniotis N. Hearing loss in low birth weight infants. American Journal of Diseases of Children 1982;136(7):602‐4. - PubMed
Beckham 1982
    1. Beckham RW, Mishoe SC. Sound levels inside incubators and oxygen hood used with nebulizers and humidifiers. Respiratory Care 1982;27(1):33‐40. - PubMed
Birnholz 1983
    1. Birnholz JC, Benacerraf BR. The development of human fetal hearing. Science 1983;222(4623):516‐8. - PubMed
Blackburn 1998
    1. Blackburn S. Environmental impact of the NICU on developmental outcomes. Journal of Pediatric Nursing 1998;13(5):279‐89. - PubMed
Blomkvist 2005
    1. Blomkvist V, Eriksen CA, Theorell T, Ulrich R, Rasmanis G. Acoustics and psychosocial environment in intensive coronary care. Occupational and Environmental Medicine 2005;62(3):e1. - PMC - PubMed
Bowden 2000
    1. Bowden V, Greenberg C, Donaldson N. Developmental care of the newborn. Online Journal of Clinical Innovations 2000;15:1‐77.
Brandon 2007
    1. Brandon DH, Ryan DJ, Barnes AH. Effect of environmental changes on noise in the NICU. Neonatal Network 2007;26(4):213‐8. - PubMed
Bremmer 2003
    1. Bremmer P, Byers JF, Kiehl E. Noise and the premature infant: physiological effects and practice implications. Journal of Obstetric, Gynecologic, and Neonatal Nursing 2003;32(4):447‐54. - PubMed
Byers 2006
    1. Byers JF, Waugh WR, Lowman LB. Sound level exposure of high‐risk infants in different environmental conditions. Neonatal Network 2006;25(1):25‐32. - PubMed
Carter 1991
    1. Carter BS, Wilkening RB. Prevention of hearing disorders: neonatal cause of hearing loss. Seminars in Hearing 1991;12:154‐91.
Catlett 1990
    1. Catlett AT, Holditch‐Davis D. Environmental stimulation of the acutely ill premature infant: physiological effects and nursing implications. Neonatal Network 1990;8(6):19‐26. - PubMed
Chang 2001
    1. Chang YJ, Lin CH, Lin LH. Noise and related events in a neonatal intensive care unit. Acta Paediatrica Taiwanica 2001;42(4):212‐7. - PubMed
Conner 1999
    1. Conner JM, Nelson EC. Neonatal intensive care: satisfaction measured from a parent's perspective. Pediatrics 1999;103(1 Suppl E):336‐49. - PubMed
Douek 1976
    1. Douek E, Dodson HC, Bannister LH, Ashcroft P, Humphries KN. Effects of incubator noise on the cochlea of the newborn. Lancet 1976;2(7995):1110‐3. - PubMed
Elander 1995
    1. Elander G, Hellström G. Reduction of noise levels in intensive care units for infants: evaluation of an intervention program. Heart and Lung 1995;24(5):376‐9. - PubMed
EPA 1974
    1. Environmental Protection Agency, Office of Noise Abatement and Control. Information on levels of environmental noise requisite to protect public health and welfare with an adequate margin of safety (Report No. 5509‐74‐004). Washington, DC: Government Printing Office, 1974.
Fisch 1983
    1. Fisch L. Integrated development and maturation of the hearing system. A critical review article. British Journal of Audiology 1983;17(3):137‐54. - PubMed
Gray 2004
    1. Gray L, Philbin MK. Effects of the neonatal intensive care unit on auditory attention and distraction. Clinics in Perinatology 2004;31(2):243‐60. - PubMed
Hall 2000
    1. Hall JW 3rd. Screening for and assessment of infant hearing impairment. Journal of Perinatology 2000;20(8 Pt 2):S113‐21. - PubMed
Higgins 2003
    1. Higgins JPT, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta‐analyses. BMJ 2003;327(7414):557‐60. - PMC - PubMed
Higgins 2011
    1. Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Intervention. Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.
Hétu 1994
    1. Hétu R. Mismatches between auditory demands and capacities in the industrial work environment. Audiology 1994;33(1):1‐14. - PubMed
Jobe 2014
    1. Jobe AH. Sensory deprivation in private rooms in the NICU. The Journal of Pediatrics 2014;164(1):1. - PubMed
Johnson 2003
    1. Johnson AN. Adapting the neonatal intensive care environment to decrease noise. Journal of Perinatal Neonatal Nursing 2003;17(4):280‐8. - PubMed
Kawada 2004
    1. Kawada T. The effect of noise in the health of children. Journal of Nippon Medical School 2004;71(1):5‐10. - PubMed
Kent 2002
    1. Kent WD, Tan AK, Clarke MC, Bardell T. Excessive noise levels in the neonatal ICU: potential effects on auditory system development. The Journal of Otolaryngology 2002;31(6):355‐60. - PubMed
Kingdom 2011
    1. Kingdom SE, Smith AP. Psychosocial risk factors for work‐related stress in Her Majesty's Coastguard. International Maritime Health 2011;62(3):200‐5. - PubMed
Lary 1985
    1. Lary S, Briassoulis G, Vries L, Dubowitz LM, Dubowitz V. Hearing threshold in preterm and term infants by auditory brainstem response. Journal of Pediatrics 1985;107(4):593‐9. - PubMed
Lasky 1995
    1. Lasky R. Sound in the NICU and its effects on the newborn. Report of the Tenth Canadian Ross conference in Pediatrics. Montreal: Abbott Laboratories, 1995.
Lasky 2009
    1. Lasky RE, Williams AL. Noise and light exposures for extremely low birth weight newborns during their stay in the neonatal intensive care unit. Pediatrics 2009;123(2):540‐6. - PubMed
Letko 1992
    1. Letko MD. Detecting and preventing infant hearing loss. Neonatal Network 1992;11(5):33‐8. - PubMed
Liu 2010
    1. Liu WF, NIC/Q 2005 Physical Environment Exploratory Group. The impact of a noise reduction quality improvement project upon sound levels in the open‐unit‐design neonatal intensive care unit. Journal of Perinatology 2010;30:489‐96. - PubMed
Liu 2012
    1. Liu WF. Comparing sound measurements in the single‐family room with open‐unit design neonatal intensive care unit: the impact of equipment noise. Journal of Perinatology 2012;32:368‐73. - PubMed
Lotas 1992
    1. Lotas MJ. Effects of light and sound in the neonatal intensive care unit environment on the low‐birth‐weight infants. NAAACOG's Clinical Issues in Perinatal and Womens Health Nursing 1992;3(1):34‐44. - PubMed
Magann 2005
    1. Magann EF, Evans SF, Chauhan SP, Nolan TE, Henderson J, Klausen JH, et al. The effects of standing, lifting and noise exposure on preterm birth, growth restriction, and perinatal death in healthy low‐risk working military women. The Journal of Maternal‐Fetal and Neonatal Medicine 2005;18(3):155‐62. - PubMed
Maragakis 2008
    1. Maragakis LL, Winkler A, Tucker MG, Cosgrove, SE, Ross T, Lawson E, et al. Outbreak of multidrug‐resistant serratia marcescens infection in a neonatal intensive care unit. Infection Control and Hospital Epidemiology 2008;29(5):418‐23. - PubMed
Matook 2010
    1. Matook SA, Sullivan MC, Salisbury A, Miller RJ, Lester BM. Variation of NICU sound by location and time of day. Neonatal Network 2010;29(2):87‐95. - PubMed
Mitchell‐Dicenso 1996
    1. Mitchell‐Dicenso A, Guyatt G, Paes B, Blatz S, Kirpalani H, Fryers M, et al. A new measure of parent satisfaction with medical care provided in the neonatal intensive care unit. Journal of Clinical Epidemiology 1996;49(3):313‐8. - PubMed
Morag 2011
    1. Morag I, Ohlsson A. Cycled light in the intensive care unit for preterm and low birth weight infants. Cochrane Database of Systematic Reviews 2011, Issue 1. [DOI: 10.1002/14651858.CD006982.pub2] - DOI - PubMed
Morris 2000
    1. Morris BH, Philbin MK, Bose C. Physiological effects of sound on the newborn. Journal of Perinatology 2000;20(8 Pt 2):S55‐60. - PubMed
Ohlsson 2009
    1. Ohlsson A. NIDCAP: new controversial evidence for its effectiveness. Pediatrics 2009;124(4):1213‐5. - PubMed
Ohlsson 2013
    1. Ohlsson A, Jacobs SE. NIDCAP: A systematic review and meta‐analyses of randomized controlled trials. Pediatrics 2013;131(3):e881‐93. - PubMed
Perlman 2001
    1. Perlman JM. Neurobehavioural deficits in premature graduates of intensive care ‐ potential medical and neonatal environmental risk factors. Pediatrics 2001;108(6):1339‐48. - PubMed
Philbin 1999
    1. Philbin MK, Robertson A, Hall JW 3rd. Recommended permissible noise criteria for occupied, newly constructed or renovated hospital nurseries. The Sound Study Group of the National Resource Center. Journal of Perinatology 1999;19(8 Pt 1):559‐63. - PubMed
Philbin 2000
    1. Philbin MK. The influence of auditory experience on the behavior of preterm newborns. Journal of Perinatology 2000;20(8 Pt 2):S77‐87. - PubMed
Philbin 2002
    1. Philbin MK, Gray L. Changing levels of quiet in an intensive care nursery. Journal of Perinatology 2002;22(6):455‐60. - PubMed
Pineda 2014
    1. Pineda RG, Neil J, Dierker D, Smyser CD, Wallendorf M, Kidokoro H. Alterations in brain structure and neurodevelopmental outcome in preterm infants hospitalized in different neonatal intensive care unit environments. Journal of Pediatrics 2014;164(1):52‐60. [PUBMED: 24139564] - PMC - PubMed
Pinheiro 2011
    1. Pinheiro EM, Guinsburg R, Nabuco MA, Kakehashi TY. Noise at the neonatal intensive care unit and inside the incubator. Revista Latino‐Americana de Enfermagem 2011;19(5):1214‐21. - PubMed
Ramesh 2009
    1. Ramesh A, Suman Rao PN, Sandeep G, Nagapoornima M, Srilakshmi V, Dominic M, et al. Efficacy of a low cost protocol in reducing noise levels in the neonatal intensive care unit. Indian Journal of Pediatrics 2009;76(5):475‐8. - PubMed
Reader 2007
    1. Reader TW, Flin R, Mearns K, Cuthbertson BH. Interdisciplinary communication in the intensive care unit. British Journal of Anaesthesia 2007;98(3):347‐52. - PubMed
RevMan 2014 [Computer program]
    1. The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.
Rubel 1985
    1. Rubel EW. Strategies and problems for future studies of auditory system development. Acta Otolaryngology 1985;421:114‐28. - PubMed
Schell 2006
    1. Schell LM, Gallo MV, Denham M, Ravenscroft J. Effects of pollution on human growth and development: an introduction. Journal of Physiological Anthropology 2006;25(1):103‐12. - PubMed
Sittig 2011
    1. Sittig SE, Nesbitt JC, Krageschmidt DA, Sobczak SC, Johnson RV. Noise levels in a neonatal transport incubator in medically configured aircraft. International Journal of Pediatric Otorhinolaryngology 2011;75(1):74‐6. - PubMed
Stennert 1978
    1. Stennert E, Schulte FJ, Vollrath M, Brunner E, Frauenrath C. The etiology of neurosensory hearing defects in preterm infants. Archives of Otorhinolaryngology 1978;221(3):171‐82. - PubMed
Suresh 2004
    1. Suresh G, Horbar JD, Plsek P, Gray J, Edwards WH, Shiono PH, et al. Voluntary anonymous reporting of medical errors for neonatal intensive care. Pediatrics 2004;113(6):1609‐18. - PubMed
Taheri 2010
    1. Taheri P, Abbasi E, Abdeyazdan Z, Fathizadeh N. The effects of a designed program on oxygen saturation and heart rate of premature infants hospitalized in neonatal intensive care unit of Al‐Zahra hospital in Isfahan in 2008‐2009. Iranian Journal of Nursing and Midwifery Research 2010;15(2):66‐70. - PMC - PubMed
Trevisanuto 2011
    1. Trevisanuto D, Camiletti L, Doglioni N, Cavallin F, Udilano A, Zanardo V. Noise exposure is increased with neonatal helmet CPAP in comparison with conventional nasal CPAP. Acta Anaesthesiologica Scandinavica 2011;55(1):35‐8. - PubMed
Wachman 2011
    1. Wachman EM, Lahav A. The effects of noise on preterm infants in the NICU. Archives of Disease in Childhood. Fetal and Neonatal Edition 2011;96(4):F305‐9. - PubMed
Westrup 2003
    1. Westrup B, Stjernqvist K, Kleberg A, Hellström‐Westas L, Lagercrantz H. Neonatal individualized care in practice: a Swedish experience. Seminars in Neonatology 2002;7(6):447‐57. - PubMed
Winkel 1978
    1. Winkel S, Bonding P, Larsen PK, Roosen G. Possible effects of kanamycin and incubation in newborn children with low birth weight. Acta Paediatrica Scandinavica 1978;67(6):709‐15. - PubMed
Zangaro 2007
    1. Zangaro GA, Soeken KL. A meta‐analysis of studies of nurses' job satisfaction. Research in Nursing and Health 2007;30(4):445‐58. - PubMed

MeSH terms