I don't know if this will help - but I'll share my experiences with you....
One of my sons, Tom aged 7 diagnosed mild Cerebral Palsy (aged 3), Autism and SPD (aged 6).
My knowledge of Tom's sensory issues are that he is over sensitive to sound, under sensitive to touch, some times over sensitive to smell.
So, noises that you and I probably wouldn't think of, say a pan of bubbling water? the checkout beeps? the noise of being inside a moving car? being in a school playground? - We accept this as 'background noise' -Tom however can't ignore these sounds, he hears it all at once whirring through his head as well as contending with his own thoughts. So maybe a conversation with mummy and daddy - we have to make sure only one of us talks at the same time, the tv can't be on or he doesn't hear what we're saying because his brain will be listening in on that.... We discovered head phones and ear defenders help with this. When we would go into town - all of a sudden he would go into a meltdown and we had no idea why and then in turn get stressed, now we think, what could it be? too much chattering? music? cars going past?
The OT has helped us to think about all the noises that go on at once - like right now, the radio is on in the kitchen, the tumble dryer is on, my husband is talking to me, I can hear the tag rattling on the dog as he walks round, I can hear my other son playing his XBox.... All of this could be, on an off day - far too much for Tom. (He is in his room with the door shut playing his Leapster with headphones on)
Touch - so Tom doesn't feel heat or pain like you and I. I would take him to the doctors thinking he was going deaf because he was shouting - it turns out he has perforated ear drums! Or when he won't eat and just wants to sleep - never told me anything - I discovered while arguing with him about how the queen says everyone must brush their teeth - he had 11 mouth ulcers - he hadn't said a word. We bought some bits of eBay, believe it or not, that had diagrams to help him show us if he was in pain and where it was. Tom loves to be gently scratched all over, you know like your mum might've done on your back when you were little and you were on her knee? I know my mum used to! Except Tom wants it on his back, knees, arms, feet - everywhere! When you do this, he totally zones out... until you stop! His electric blanket he likes on a lot! He loves a fairly warm shower! So it's fair that he needs extra touching to keep himself at ease. The OT said when he asks to be scratched, his body is needing some extra sensory input to regulate itself - this finds it's way into Tom's moods! If we stay on top of his needs with what is called a sensory diet by OT's, he stops getting SOOOOO excited about things or SOOOOO cross/upset about things. Tom wears a sensory hug shirt all day every day as the tight pressure it provides him seems to keep him more content. Don't get me wrong - he still has melt downs and tantrums, but they are a little less often and a little less severe! Easier to settle.
If Tom is having a bad day, he's in a bad mood say, nothing smells right to him. Even his favourite dinners? his bedtime bear he'll say stinks...
An OT will assess and find out what and where the Sensory needs lay.. It can be visual, hearing, touch, hearing, taste or propreoceptive (excuse spelling). A sensory diet may be provided for your child's needs. It is a group of exercises - Tom's is being rolled up in gym mats (he calls this the hot dog) and you apply pressure on and off going up and down (putting mustard and ketchup on the hot dog!) - he pulls himself along a bench, he does some activities while sitting or laying on a gym ball! The list of possibilities is endless! A trampoline also helped Tom.
I don't know if any of this helped! But I had an interesting journey writing it!!
Any other questions... I'd be happy to try and help!