Final answer:
Gender is not a variable that creates our experience of breathing.
Step-by-step explanation:
Out of the given options, gender is NOT a variable that creates our experience of breathing. Breathing is primarily controlled by the respiratory centers in the brain, which are regulated by factors such as the level of physical activity, respiratory muscle strength, breathing volume, and rate of respiration. The other options mentioned (breathing volume, rate, sound, activity level) are all variables that can influence our experience of breathing.