Having worked in an arcade, I can understand why someone would have turned off some, if not all, of the attract mode sounds. They had this awful "Chase the Rainbow" machine in the one I occasionally worked at that would shout insipid things like "Chase the rainbow shining bright!" and "Come play Chase the Rainbow with me!" every few minutes. Thankfully, I rarely had to work in there for more than four hours a day, so I only heard each saying about 20-25 times daily.
Since nobody ever came into that arcade, I took up building things out of used redemption tickets - baskets, cars, houses, etc - to pass the time and help me block out the sounds. I also learned how to yo-yo, wrote stories on the back of tickets for the next employee who had to work in there to read, and tested out every prize at the redemption counter. Sadly, in the most evil form of torture that there is, I was not allowed to play the games...
Anyway, back on topic. Yeah, I wish you could shut that off too, but I haven't found an option for it.