K.S.
I am more familiar with the more general term of Sensory Processing Disorder (SPD). Kids can be sensory avoiding (have a low tolerance for noise, textures, smells, tastes, or movement) or sensory seeking (they seek higher than normal amounts of those same inputs). All of us have a combination and to varying degrees. Where it becomes a problem and should be diagnosed and treated (IMO) is when it starts to interfere with a child being able to participate in activities that they want or need to do. For example, my DS really, really wanted to play on an indoor soccer team, but the noise would cause him to curl up in a moaning ball on the gym floor (sensory avoiding of sound). Also when he started preschool he was starting to make enemies out of his classmates because he would crash into everyone (sensory seeking for certain tactile and vestibular inputs).
I always recommend "The Out-of-Sync Child" to parents wondering about their child. They have clear explanations of what to look for. If it seems like the SPD is a problem for your child find a developmental pediatrician or an OT who specializes in sensory issues.