Advances in Neonatal Care:
WITT, CATHERINE L. MS, RNC, NNP
I am pleased that Advances in Neonatal Care is able to offer this supplement addressing the issue of noise in the Neonatal Intensive Care Nursery. This supplement includes several important published papers on the problem of noise and our responsibility as nurses to make improvements for the sake of our patients and ourselves.
The detrimental effects of noise on the preterm neonate have been well documented in the literature. Physiologic responses such as fluctuations in heart rate, blood pressure, respiratory rate, and oxygen saturation have been demonstrated.1,2 Research has also suggested there are long-term effects to exposure to noise in the NICU. While it is difficult to determine causes of decreased hearing acuity in preterm infants, we should be concerned when noise levels exceed that which has been shown to be detrimental to the hearing in older children and adults. Besides the potential for long-term loss of hearing, there is also concern that prolonged exposure to environmental noise contributes to long-term problems such as attention difficulties.3 In utero, sounds are filtered through amniotic fluid and the fetus is protected from low, mid, and high-frequency sounds and can focus on the maternal voice. Once in the NICU environment, the preterm infant is exposed to a wide variety of air born sounds at unpredictable frequency. The preterm neonate has a limited ability to distinguish various sounds, such as voices, from mechanical sounds and has difficulty habituating to or tuning out these sounds.3–5
Environmental sounds can be detrimental to staff as well. The National Institute on Deafness and Other Communication Diseases estimates that 10% of people aged 20 to 69 years have suffered permanent hearing damage, much of it secondary to exposure to excessive environmental noise.6,7 In addition to hearing loss, adults have many of the same physiologic changes as premature infants: increased heart rate and blood pressure and increase in cortisol levels. Constant exposure to noise increases fatigue levels, requires increased energy to perform tasks, and makes it difficult to communicate with others.
The 2007 recommended Standards for Newborn ICU Design include the following:
* In infant rooms and adult sleep areas, the combination of continuous background sound and operational sound shall not exceed an hourly Leq of 45 dB and an hourly L10 of 50 dB, both A-weighted slow response. Transient sounds or Lmax shall not exceed 65 dB, A-weighted, slow response in these rooms/areas.
* In staff work areas, family areas, and staff lounge areas, the combination of continuous background sound and operational sound shall not exceed an hourly Leq of 50 dB and an hourly L10 of 55 dB, both A-weighted slow response. Transient sounds or Lmax shall not exceed 70 dB, A-weighted, slow response in these areas.8(p27)
As 2 articles in this supplement report, sound levels in NICUs frequently exceed recommended levels.9–11 We are often not aware of the level of noise around us.9 We have become used to elevated noise levels in our environment, in shopping centers, movie theaters, sporting events, and other areas. This desensitization (and possible hearing loss among nurses) may contribute to our unawareness. It will require a concentrated effort on the part of everyone in the NICU to create an environment that is not harmful to our patients and families, and not detrimental to staff.
As nurses we have a responsibility to advocate for healthy environments. We must ensure that the standards set for noise in the NICU are met. We must support continued research into the effects of noise on the developing brain. We must strive to educate our patients, families, and colleagues about the detrimental effects of environmental noise, not only in the NICU but in our environment as a whole. There are some things that happen in the NICU that we cannot control. Noise is not one of those.
1. Bremmer P, Byers JF, Kiehl E. Noise and the premature infant: physiological effects and practice implications. Journal of Obstetric, Gynecologic, and Neonatal Nursing
2. Graven SN. Sound and the developing infant in the NICU: conclusions and recommendations for care. Journal of Perinatology
. 2000;20(8 pt2):S1–S93.
3. Gray L, Philbin MK. Effects of the neonatal intensive care unit on auditory attention and distraction. Clinics in Perinatology
4. Kreuger C, Wall S, Parker L, Nealis R. Elevated sound levels within a busy NICU. Neonatal Network
5. Willimas A, van Drongelen W, Lasky R. Noise in contemporary neonatal intensive care. Journal of the Acoustical Society of America
9. Walsh W, McCullough K, White R. Room for improvement: nurses' perceptions of providing care in a single room newborn intensive care setting. Advances in Neonatal Care
10. Brandon DH, Ryan DJ, Barnes AH. Effect of environmental changes on noise in the NICU. Neonatal Network
11. Darcy AE, Hancock LE, Ware EJ. A descriptive study of noise in the neonatal intensive care unit. Advances in Neonatal Care