Through my reading on the internet I came across a supplement called Gaba. I understand it helps people with spasmodic dysphonia making it easier to talk . I took it before probably in low dosage and couldn't see any benefits from it . Now I've taken it in a larger dosage 750 mgs tablets and people have been saying you are getting your voice back not only that but I noticed that if I take the Gaba I can tolerate perfume better many times . Don't go over board with gaba hits your stomachk , head- feel sick and can weaken you too much ( Still best to get away from offending chemical) The reaction I get from gas, perfumes, etc is I'll start in involuntary yelling ,speaking , get weak to point of collapsing,- get away from chemical odor ---- get gaba in my mouth and chew it - in a very short period of time I'm all well again. I often take it early in the morning and if I know I'm going into perfume etc chemical odor areas I think I might increase dosage and take it before I go to bed . Some have been taking 1500mgs and helps sleep. though I don't think I have much trouble sleeping.