What can I do to reduce the noise on a foam layout top with E/Z track when I run the trains?
Not much really.
The thicker the foam is, the less reverberation (noise) you hear. A 1 inch layer with nothing under it is loud.....it works like a drum in effect.
A 2 inch layer on plywood is still noisy. although not as pronounced as the 1 inch alone. The hollow space in the plastic roadbed of the EZ Track just adds to the problem.
I know that once you get your scenic ground cover in place, things will dampen down quite significantly. But until that happens, I'm afraid it's going to be hard to quiet things down. This is one reason, among others, that I use plywood sub-roadbed with cork roadbed and sectional/flextrack.
Sid
As Sid mentioned, it is the hollow space underneath that causes the noise. When we had the EZ track on carpet, it was very quiet. Placing the track on rigid foam won't dampen the sound much, may even make it worse.
Get a roll of Woodland Scenics N scale roadbed. The 3mm thickness and 1-1/4" width is just right to fill the voids. Cut to length and glue under the bed with rubber cement or tape in place with small pieces of duct tape.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXZE06&P=0
Bob