I've had excellent results with MRC Sounder (Sound only) Decoders.  They are easily installed with only two connections and have multiple sound options.  There are two types - steam  or diesel.

The last part of the address should read:  ....ezpage=1

I had the same problem when I purchased my E-Z Command.  I found that the instruction booklet was incorrect and when I downloaded the instructions from Bachmann there was a slight ,but significant difference. Try and print the following: www.bachmanntrains.com/home-usa/ezcommand.php?ezpage+1