Noise levels in NICUs have been shown to be consistently louder than guidelines provided by the American Academy of Pediatrics (AAP). These guidelines stipulate that the noise levels that the hospitalized infants are exposed to should not exceed 45 dB, A-weighted (dBA), averaged over one hour and the sound pressure level should not exceed 55 dBA for 10% of the measurement duration. Noise measured both inside and outside an incubator show guidelines are frequently exceeded throughout the day.
Looking specifically at the sources of noise in the NICU, most are life-critical devices or communication between caregivers, which is often essential for proper care of patients.
|Source||dBA||Other Sources > 45dBA|
|Incubator alarm||68||Telephone ringing|
|IV pump alarm||61-78||Intercom bell ringing|
|General conversation||58-64||HF oscillatory ventilator|
|CPAP (depending on flow)||54-89||Trolleys being wheeled around|
While excessive noise is shown to be detrimental to the well-being of the hospitalized infant, proper exposure to human voices, especially in directed communication between the infant and parents, is proving to be beneficial. A correlation exists between the amount of adult language the preterm infant is exposed to in the NICU and the amount of reciprocal vocalizations and meaningful early conversations. It was noted that hospitalized infants at 32 weeks were particularly devoid of exposure to human speech because they were “often still in an isolette [incubator], where it has been shown that little language is audible.” The long-term effects of this are marked. Analysis at 7- and 18-month post discharge shows a correlation between NICU voice exposure and scores in several types of cognitive and language scores.
Single family rooms (SFR) have provided many improvements to the NICU experience, both for patients and their families. Sound levels in SFRs have been found to decrease very slightly though, given the life support equipment that’s still needed in the room. A comparison from the literature between different room types is shown here.
|Unit Type||Leq (dB)|
|Open unit (level 3)||59|
|SFR without vent support||52|
|SFR (level 3) with vent support||53|
|Approach||Challenges Noted In Literature|
|NICU Reconstruction||• Minimal changes (4dB) to average sound levels and no change to sound levels exceeded 10% of the time
• Levels remained in excess of AAP guidelines
|Single Family Rooms||• Single rooms not quieter than double rooms depending on ventilatory gear used
• Open ward and single rooms differ by +0.7 and -4.3dB
|Staff Education||• No decrease in noise levels after implementing noise awareness program|
|Light Warnings||• After implementing, no significant difference in noise levels|
|Ear Coverings or
|• Concerns about adhesive’s effect on delicate skin
• Reduces exposure to adult words, impacting cognitive development
• IRB refused to approve study using earplugs
• Nursing concerns over aspiration, frequent repositioning
|Moderating Alarms||• Concerns about lowering alarm volumes resulting in missed alarms
• Replacing older gear with new