Slot machines are just one of the many options for gamblers in search of financial success and adventure. But in many ways they embody the “style-over-substance” approach that gambling venues have now embraced, as they strive to keep their customers coming back no matter how much money they lose or how deeply into debt they plunge.

At one time the slot machine (a.k.a. “the one-armed bandit”) was a simple device with a simple premise. All the user had to do was insert a coin, pull a lever down and sit back and wait to see if three cherries would turn up. Generally players would come with a roll of quarters and quit when the last one was gone, most often walking away with empty pockets but occasionally heading home with a bag full of jingling jackpot winnings.

The object of the game hasn’t changed over time, but the slot machine itself has changed dramatically. The modern slot machine is more like an entertainment center than a gambling device, greeting the user with flashing imagery, stereo sound effects and innumerable interactive playing options that mimic the variety and diversity of video games.

Sound in particular has come into increased use in slot machines. Up through the early 1990s, the average one-armed bandit featured only 15 sound effects. But that number has now soared to over 400. This cacophony of audio enhancement celebrates the gambler’s success while making the victorious slot player the object of everyone’s admiring attention. When someone hits the mother lode on a modern slot machine, everyone in the casino will hear about it, and in the process absorb the not-so-subtle message that winning money while gambling is not only possible, but to be expected.

Full of Sound and Fury, Signifying Gambling Dependency

But what kind of impact does this panorama of stereo sound actually have on gambling behavior? A research team from the Department of Psychology at the University of Waterloo in Ontario set out to discover the answer. The team recruited 96 gamblers to participate in a study that compared responses to games played on two different slot machine simulators: one designed to bombard users with a virtual symphony of sound effects and another that featured no sound effects whatsoever. In their visual aspects as well as overall playing style, the two machines offered an otherwise identical gambling experience. Players were given the opportunity to win real money in both games, thereby ensuring authentic emotional responses.

In interviews conducted after the experiment had concluded, 66 out of 91 participants with a firm opinion said they preferred playing on the noisier, sound-enhanced slot machine simulators. Interestingly, playing on machines with a multitude of sound effects also tricked gamblers into overestimating their success; when asked to guess how many times they had won money, the average response for each gambler was 36.5 times out of 100 on the sound-enhanced machines and 33.5 times on the quieter alternative. Researchers knew the real answer for both machines was 28, since the games had been rigged to produce consistent results. Additionally, skin conductance tests revealed the gamblers experienced higher bursts of arousal when playing on the simulators that offered sound accompaniment, with arousal levels spiking higher based on the size of the win.

Before conducting the experiment, the researchers evaluated participants for problem gambling and found that 19 of them met the criteria for a compulsive gambling disorder. Of the remainder, 31 were judged to be at moderate risk for developing a gambling problem somewhere down the line, while 46 exhibited no problem gambling tendencies and were not believed to be at risk.

But this categorization did not correlate with any particular results in the experiment itself. Members of all three categories reported similar impressions and were impacted physiologically to about the same degree. Based on this study, it appears the response to sound effects in slot machines has universal characteristics, increasing arousal and excitement in all users and tricking them into believing they are winning more often than they really are. Past research has found a relationship between pathological gambling and high levels of arousal, while also uncovering the tendency of gambling addicts to underestimate the size of their losses, so clearly these findings are notable and significant.

Gambling’s Biggest and Most Consistent Winner? Addiction

Pathological gambling addiction provides the classic example of a slippery slope phenomenon at work. This condition develops slowly but surely, with the lure of gambling gradually increasing until victims find themselves trapped by the steely jaws of addiction. With such a disorder, small factors can have an exaggerated effect over time, and it is reasonable to conclude that people repeatedly exposed to the multimedia lollapalooza of the modern slot machine are at greater risk of developing a dependency.

More research into the possible connection between sound effects in slot machines and compulsive gambling is needed. But casinos wouldn’t be purchasing these juiced-up versions of a traditionally dependable moneymaker unless they were convinced slot players would respond favorably (by playing more, in other words)—and the immense profitability of these businesses proves their owners know what they are doing.


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