A comparison of two designs for earcons conveying pulse oximetry information

We performed a randomised controlled trial comparing two kinds of earcons that could provide intermittent pulse oximetry information about a patient's oxygen saturation (SpO ) and heart rate (HR). Timbre-earcons represented SpO levels with different levels of timbre, and pitch-earcons with different levels of pitch. Both kinds of earcons represented HR with tremolo. Participants using pitch-earcons identified SpO levels alone, and both SpO plus HR levels, significantly better than participants using timbre-earcons: