A: Sensory processing disorder (SPD) is a condition that affects how your brain processes sensory information (stimuli). Sensory information includes things you see, hear, smell, taste, or touch. SPD can affect all your senses, or just one. SPD usually means you are overly sensitive to stimuli that other people are not. Put very simply the messages received through the senses get muddled up.
https://www.sensoryintegrationeducation.com/pages/what-is-si