Which system is responsible for detecting changes in head position through the inner ear?

The vestibular system is the correct choice because it specifically consists of structures in the inner ear that are crucial for sensing changes in head position and motion. This system includes the semicircular canals and otolith organs (saccule and utricle), which detect rotational and linear accelerations, respectively. The sensory information from these structures helps maintain balance, spatial orientation, and coordination of movements.

In contrast, the somatosensory system relates to sensations from the skin, muscles, and joints, providing feedback about body position and movement through touch and proprioception. The visual system contributes to spatial awareness and balance but primarily relies on visual information rather than changes in head position. The cognitive system refers to higher-level functions like memory and decision-making and does not directly pertain to physical changes in head position. Thus, the vestibular system is uniquely tasked with detecting and responding to head movements.