Adding a beacon to the variable-pitch pulse oximeter sound may help clinicians identify when, and by how much, a neonate's SpO2 deviates from the target range, particularly during patient transport situations when auditory information becomes essential.

Recent guidelines recommend oxygen saturation (SpO2) levels of 90%-95% for preterm neonates on supplemental oxygen but it is difficult to discern such levels with current pulse oximetry sonifications. We tested (1) whether adding levels of tremolo to a conventional log-linear pulse oximetry sonification would improve identification of SpO2 ranges, and (2) whether adding a beacon reference tone to conventional pulse oximetry confuses listeners about the direction of change. Participants using the Tremolo (94%) or Beacon (81%) sonifications identified SpO2 range significantly more accurately than participants using the LogLinear sonification (52%). The Beacon sonification did not confuse participants about direction of change. The Tremolo sonification may have advantages over the Beacon sonification for monitoring SpO2 of preterm neonates, but both must be further tested with clinicians in clinically representative scenarios, and with different levels of ambient noise and distractions.

Pulse oximeters monitor a patient’s heart rate and oxygen saturation (SpO2) via visual and auditory displays. Heart rate is represented by the beep rate and SpO2 by beep pitch. However, the auditory display alone does not always accurately inform clinicians of the patient’s actual SpO2 level. Moreover, neonates have special oxygen needs that mean current pulse oximetry sounds are inadequate. In three studies we tested potentially improved pulse oximetry sounds for monitoring critically ill neonates. The control condition was a logarithmic mapping of percentage oxygen saturation to beep frequency in Hz. A sonification that added an intermittent reference tone, or “beacon” when SpO2 was out of the target range proved highly effective. We discuss the theoretical and practical implications of the findings.