The problem of players missing the clanking of coins was one of the primary factors that kept coinless technology off of slot floors for so long. Eventually, however, the benefits of coinless games won out and many casinos are now making the switch. Still, the manufacturers tried to mitigate the pain, slightly, by programming coin-clanking audio into the ticket-in ticket-out machines.
But don’t worry. Just as a few single-deck blackjack games continue to survive in the age of the dealing shoe, most casinos will always offer slots that use coins to appease customers who wouldn’t yank without the clank.