The committee members are listed here and one should feel free to contact them, especially if you are in their district.
If you are able to attend, the hearing is Nov. 29 2:00 pm in 2154 Rayburn House Office Building.
To be clear, this is a committee hearing from a lame duck congress. No legislation is being considered at present. There will be some science, much politics and, I expect, more than a little theater (although I admit where politics ends and theater begins is not well defined).
Word is that the hearing will include government and non government members in two panels.
Alan Guttmacher, NIH NICHD
Coleen Boyle, CDC
Bob Wright, Autism Speaks
Scott Badesch, Autism Society
Mark Blaxill, Safe Minds
Rebecca Landa, Center for Autism and Related Disorders Kennedy Krieger Institute