Next time you’re at the casino and your heart races at the sound of a winning jingle, make sure you look down at the counters for the real story.

In a recent study on slot machine sounds, Waterloo Professor Mike Dixon, in the Department of Psychology, found that celebratory music caused players to perceive they were winning even when they experienced a loss.

On modern slot machines players can wager on multiple lines.  For example, a player can wager 10 cents on each of 9 lines for a total bet of 90 cents per spin. When they spin and lose all 90 cents, the machine goes quiet.  When they spin and win more than their wager the machine celebrates the win with exciting animations and catchy winning jingles.  When the player spins and wins back say 30 cents, the machine still plays a winning jingle despite the fact that the player lost 60 cents on that spin.

Losses disguised as wins

“We call them ‘losses disguised as wins’ because they’re monetary losses to the player but the sound makes you feel like you’ve won,” says Dixon.

In the study, 96 gamblers played on slot machine simulators that dealt them 28 wins but also 28 losses disguised as wins. “One of the ways we verified their impressions at the end of the study is to ask, ‘On how many spins did you win more than you wagered?’ The true number was 28 but they overestimated and miscategorized some of these losses as wins,” says Dixon.

With modern slot machines featuring hundreds of lines and averaging over 400 sounds, keeping track of whether you won or lost by watching the lines can be overwhelming.  Dixon thinks that some people rely on the sounds to tell them if they won or lost.

Playing with your memory

Dixon and his colleagues ran the study twice, once with the sound on and once with the sound off. While gamblers overestimated their wins in both cases, players misremembered winning more often with the sound on.

When surveyed about the experience, most participants said they preferred the excitement generated by playing with the sound on. Dixon and his colleagues are now exploring the effects of negative sounds on the gambling experience.

Dixon says overestimating wins can also have an impact on a player’s memory of the gambling experience. “We all have a tendency to focus on our wins and discount our losses,” says Dixon.

His advice is simple: “After playing, check your wallet.”