Bone conduction noise exposure via ventilators in the neonatal intensive care unit

Objectives/Hypothesis To demonstrate that neonatal ventilators can expose patients to high noise levels through bone conduction (BC) as well as air conduction (AC). Study Design Observational study. Methods Three ventilators and various settings on a positive airway pressure machine (continuous, high bilevel, and low bilevel pressure) were tested. A sound level meter was used to measure the noise levels at a set distance from the ventilator to represent AC, on the ventilator circuit to represent BC at the alveolus, and within the ventilator circuit. Results The BC sound levels (74.1, 81.1, 86, 89.2 dBC) were significantly higher than the AC sound levels (72.8, 72.9, 70, 71.7 dBC) for the jet ventilator, continuous positive airway pressure setting, low bilevel setting, and high bilevel setting, respectively (P <.001). The sound level within the ventilator circuit ranged from 94.9 to 113.2 dBC depending on the machine/setting and was significantly louder than both AC or BC for all machines/settings (P <.001). Conclusions There are concerning ventilator dependent noise levels present on and within ventilation circuitry that could be presented to the infant via BC.