Modulation disorder is one of the three types of sensory processing disorder (see more on sensory modulation disorder on the "Types of SPD" page). Sensory over-responsivity (SOR) is one of three sub-types of modulation disorder (the other two are sensory under-responsivity and sensory seeking/craving). Sensory over-responsivity in the auditory system is common in children with sensory processing disorder and may exist as a stand-alone disorder or co-exist with other types and sub-types of sensory processing disorder. This disorder is also commonly referred to as hyperacusis or auditory defensiveness. Children with this disorder exhibit an extreme sensitivity to certain sounds that would not be particularly disturbing or distressing to other people. Triggers may be high-frequency sounds, low-frequency sounds, or both high-and low-frequency sounds. In other words, the child may be sensitive to loud noises, gentle noises, or both. Modulation enables us to filter sensations, attend to those that are relevant, and screen out those that are irrelevant. In the case of sensory over-responsivity, the child's brain does not filter out the auditory information it should, and this elicits the body's pain response.

Behavioral reactions to disturbing sounds can range anywhere from mild annoyance, the "fight or flight" reaction, or a shift into sensory craving mode. When over-responsive children feel assaulted by sensory stimuli to which they are hypersensitive, they may respond by either trying to avoid the sensation or combating the sensation. When the child goes into combat mode, he will become more active, agitated, and aggressive. He will shift into sensory craving mode producing the very loud noises that he dislikes and eliciting loud noises from others. Ultimately, this will overload the child further creating a vicious cycle.

Avoidance children might cover their ears and show signs of distress and cry when encountering loud noises. He may show signs of fear and anxiety and will avoid the activities other children enjoy to avoid the trigger sounds. Children with auditory SOR are typically distressed by noises made by power tools, thunder, and fireworks. Trips to public restrooms can be scary, as the loud toilets flush on their own and hand dryers echo in the room. Movies may be unbearable as the surround sound sets off an explosion in the child's head. The school bus may incite physical ailments such as tummy aches. Infants and young children may cry when they hear a loud sneeze. Supermarkets, school cafeterias, garbage trucks, vacuum cleaners, or the sound of someone's voice may elicit visible stress. Unexpected noise may be especially problematic, and the child may run away, cry, and/or cover their ears. These children usually cope better in a quiet and calm environment as noisy environments may lead to self-regulation difficulties.

In addition to their hypersensitivity to loud noise, auditory defensive children might be acutely aware of other sounds that are not generally considered disturbing, such as the sound of a clock ticking or a small creature scratching. Some children are acutely aware of certain low-intensity and low-volume sounds and might become disorganized, upset, or annoyed upon hearing them. Young children may not realize that sound is distressing them. Parents can raise their child's awareness level by verbalizing the problem. You can say, "Was that vacuum cleaner too loud for you?" or "Does the sound of the clock ticking hurt your ears?"

Sensory over-responsivity in the auditory system may be diagnosed by an occupational therapist or a speech/language pathologist. Treatment is accomplished through Therapeutic Listening, often recommended by occupational or speech/language therapists. Therapeutic listening was developed by occupational therapist Sheila Frick and is an innovative program for providing high-quality auditory input within the context of sensory integrative treatment. More information on therapeutic listening can be found here: http://www.vitallinks.net/  For severe auditory modulation disorder, noise-reducing earplugs may be recommended by an audiologist. Several types are available that can be custom fit to the listener's needs.

With treatment, this condition can be remediated significantly or eradicated completely, so it’s important to seek help immediately if signs of auditory SOR are detected. Therapy can help the child to live a happy and successful life, which is always a primary parental goal!