stylistic:tone
Observer error

There are many factors that can play a role in the blood pressure reading by physician, such as hearing problem, auditory perception of the physician.Karimi Hosseini et al. evaluated the interobserver differences among specialists without any auditory impairment, and reported 68% of observers recorded systolic blood pressure in a range of 9.4 mmHg, diastolic blood pressure in a range of 20.5 mmHg and mean blood pressure in a range of 16.1mmHg. Neufeld et al. reported standard deviations for both systolic and diastolic readings were roughly 3.5 to 5.5 mm Hg. In general standard deviation for the diastolic pressure would be greater because of the difficulty in judging when the sounds disappear.