Potty Training Readiness Signs in children with special needs: 

https://www.healthychildren.org/English/ages-stages/toddler/toilet-training/Pages/Toilet-Training-Children-with-Special-Needs.aspx

Some children are very sensitive to loud sounds.  When a child develops a fear of the bathroom because of past experiences with toilets flushing or hand dryers, you may want to consult with your occupational therapist for assistance. 

Your OT may recommend sensory supports such as noise cancelling headphones.  There are also treatment approaches to help your child be less fearful of the sounds associated with using the bathroom. 

What parents can do at home: 

Set the “stage”: Make the bathroom a pleasant place to be.  If your child is sensitive to bright lights or odors, set up your bathroom with a night light or small lamp.  Be aware of strong odors such as perfumes, scented soaps, or unpleasant smells.   Consider installing a slow-close toilet seat so the lid does not bang loudly.  If the child is fearful of the sound of the toilet flushing, be sensitive to that and avoid flushing when your child is on the toilet or not expecting the sound. 

Be sure your child’s feet are supported while they sit on the potty.  This can be accomplished by using a footstool or investing in a short toilet (if your child is small).  Some toddler-size toilet seat inserts have handles to help a child feel more secure. This is important especially if your child has weakness in their abdomen or hips.  If your child frequently leans on walls and people, and has to push with their arms to stand up from the floor, they likely have some weakness in those postural muscles that help keep them upright. It is terribly difficult to try to urinate or have a bowel movement when the child is having to focus on staying upright! 

Consider setting aside some “special” toys for your child to use only while sitting on the toilet.  Perhaps set a timer and praise or reward your child for simply sitting on the toilet. 

Sometimes a child is better able to release their bladder/bowel when blowing their breath out against resistance.  Having the child blow bubbles or blow into a party blower can assist them in releasing their bladder. 

Public bathrooms are often more noisy/odorous/bright than home bathrooms.  If your child is very sensitive to these types of experiences, consider not using a public restroom if possible.