There is no doubt that hearings are very important to members of Congress. They are also important to the UCAR community.
"...there is a strong belief — inside and outside of Congress — that holding public hearings is one of the more important things that Congress does. In recent years, Congress has been averaging several thousand hearings per year, calling upon tens of thousands of witnesses." — Working with Congress: A Practical Guide for Scientists and Engineers, by William G. Wells, Jr.
Here are some pointers on appearing as a witness in a hearing before a congressional committee.