Ah, thanks George. So it is a modern electric high-speed train set. IMO, sound in models of electric vehicles is even less exciting than Diesel. To me steam locos get the most benefit from being equipped with sound.
Not sure what brand decoder Arnold uses. I have a Kato/Lemke ICE 4 set with factory installed (ZIMO) sound. It's cute. Most useful are the horns. Then there is the traction motor hum, cooling fans, the cutesy station announcements, and conductor's whistle. Is it worth the extra cost over non-sound decoder? I guess if you have the funds and like sound then yes. Forty dollars for a non-sound decoder seems reasonable too. It would probably cost you about that much to buy a Next18 decoder and install it yourself.
I do hope that Arnold uses good quality decoders. I have a Fleischmann steam loco with factory installed ZIMO decoder, and Minitrix seems to use Doehler & Haass decoder hardware. That is a good decoder, almost unknown in USA.
EDIT: corrected spelling