Hyper-sensitive means being extremely responsive to even minor stimuli. The antonyms for hyper-sensitive include words such as insensitive, callous, detached, unfeeling, apathetic, and indifferent. Individuals who are insensitive do not experience intense emotions or react to every small change in their environment. People who are callous are usually toughened or hardened from previous experiences. They are incapable of feeling empathy or compassion. Detached individuals are emotionally distant and disconnected. They can appear aloof, indifferent, and uninvolved. Unfeeling people do not react to stimuli because they lack sensitivity, while apathetic people lack interest and enthusiasm. Indifferent individuals are indifferent and do not care about the outcome.