Final answer:
The shift in hearing range due to changes in air pressure in the nose is linked to the balance of pressure in the inner ear, affecting the flexibility of the eardrum and the transmission of sound waves.
Step-by-step explanation:
The physiological explanation for the shift in hearing range observed when increasing or decreasing air pressure in the nose is related to the balance of pressure in the inner ear. When the air pressure changes, it affects the flexibility of the eardrum and the fluid dynamics in the inner ear, which in turn affects how sound waves are transmitted and perceived. Specifically, increased pressure can stiffen the eardrum, making it less responsive to sound vibrations, reducing hearing sensitivity, especially to lower frequencies. Decreased pressure may have the opposite effect, enhancing sensitivity to certain frequencies. Our ears are equipped with a mechanism, such as the Eustachian tube that helps to equalize the pressure in the middle ear with the atmospheric pressure, ensuring that pressure changes do not affect hearing too drastically under normal circumstances.