Slot Machines

Casinos Pic.png

This episode was written & produced by Colby Hartburg.

What do you hear when you walk into a Casino? It can feel like chaos, but each sound is carefully curated to draw you in and make you stay. One collection of sounds are scientifically and artistically designed to keep the gambler, gambling. Slot machines. This episode features interviews with Willie Wilcox, Chief Sound Designer at Scientific Games in Las Vegas, Laura Taylor, composer and sound designer for a number of slot machines across the US, and Karen Collins, who has led extensive research into the sound and music behind these games. Is it addiction or entertainment? Maybe it's both. Pull the lever and listen for yourself.


The Habit (Instrumental) by Reagan James
Glass House by Utah
Nonchalant by Watermark High
Punk Drop by Zi
Sofia by AM Architect
Whats In Front Of Me (Instrumental) by Lael
Love With Your Life (Capital Kings Remix - Instrumental) by Hollyn

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View Transcript ▶︎

[SFX: Casino Ambience]

You're listening to Twenty Thousand Hertz...The stories behind the world's most recognizable and interesting sounds. I'm Dallas Taylor.

The sound you just heard…is what casinos use to lure people in…and keep them there. There’s the sound of the cards [SFX: Cards shuffling], the chips [SFX: Chips], the craps table [SFX Craps table], but there’s one game that is particularly effective at keeping people playing. The slot machines.

[SFX: Slot machines]

[music in]

Modern Casinos earn over 70 percent of their revenue off of slots. That’s a dramatic increase from the 1970’s, when it was less than 50 percent in most casinos. A lot of that has to do with the advancements in gaming technology. Slot machines today are very different than their predecessors.

[SFX: Old slot machine]

They’re now more like video games…

[music out]

[SFX: Newer slot machine]

And there’s plenty of science and sound design that go into their creation.

Laura: There are different styles of slot machines. Obviously when you go into a casino you have a smorgasbord of slots to choose from.

This is Laura Taylor, she’s a sound designer for slot machines.

Laura: You go into the Vegas casinos, or in a smaller casino, there'll be a little corner, you'll have that gigantic Britney Spears machine with the huge curved screen.

[SFX: Music Britney Spears “Hit me Baby One More Time”]

Or you can play a Batman game, or you can play a Godzilla game, or Kiss…[SFX: Kiss “Are you ready to rock”]

It's another way to make revenue for a licensed property.

We’re probably all familiar to the traditional slots with the three wheels. You pull the handle, you wait for the cherries to line up, you win [SFX: ding ding ding!] or…you try again.

[music in]

Those are called “Stepper Machines”. But today, there’s a massive variety in slot machines. Willie Wilcox, who’s Chief Sound Designer for Scientific Games out of Las Vegas, helps break it down.

Willie: So the other kinds of slot machines, other than like a traditional stepper machine, you start getting into the new video machines, which can be stereo machines and you can also get into video versions of surround sound games.

Today’s slot machines are all about themes. As Laura mentioned, popular music is a big trend, but also movies, such as James Bond, Rocky, and Ferris Bueller’s Day Off. And all of them require sound and music.

[music out]

Willie: In order for somebody to be able to sit there and play for a long time, you don't want them to get sonically fatigued. We're generating music that is engaging, that is anticipatory, that enables somebody to sit there for a long period of time without being bored, without being irritated and feeling like somebody is taking their index finger and tapping you on the forehead and making you not want to be there.

That’s a lot of pressure to put on these sound designers. The sounds need to draw in players, but also be comfortable to listen to for long periods of time. The last thing casinos want is for you to leave due to listener fatigue. Not only that, but they’re also competing against all of the other sounds in the casino. The popular music, [SFX: Casino w/pop music] the chatter, [SFX: chatter/laughing], and the other slots [SFX: slot machines].

Willie: You're looking for music that's going to keep the player engaged [SFX: engaging music], but not detract from what they're doing. The real attraction is always the chase, always chasing what it is that you're looking to win, and making identifying sounds that help you realize that.

So if you had your eyes closed and you weren't watching, you would know from the sounds that you're hearing what's happening in the game. It should be that simple and that conclusive.

Laura: The number one rule is don't be annoying. That's always in the forefront of my mind, because somebody's going to sit down at one of these machines, and hopefully they're going to play it for a very, very long time, and they're going to hear the same sounds over and over, and so I don't want anything high-pitched. I don't want anything shrill, and I don't want anything boring.

[SFX: Slot machine music]

Laura: There has to be a lot of motion to it. It's not going to 80 beats per minute. It's going to be 130 or 140, something that moves, something that drives. Maybe if they wait long enough, you start getting little audio hints. A ding [SFX: ding], a whoosh [SFX: whoosh], just something to draw the player's attention back to the machine.

Another question slot designers have to ask themselves is how many speakers there should be and where to put them.

Willie: It's extremely important to pay attention while you're designing these slot machines, that when a player sits in a chair, and the two sets of stereo speakers, your left and right speakers that are facing the player, are positioned in a good listening position, which is just pro-audio 101.

If you have speakers that are shooting out into space, that means that the player next to you that's playing is going to hear all your speakers. [SFX: slot machines in background] Do you really want to hear what the player next to you is doing or do you want to hear what you're doing?

So speaker placement is extremely important, so is speaker type. If you have too small of speakers, then you've got a lot of super high end frequency responses, and not a lot of mid-range and lower frequency responses, which make the sound much more fatiguing to the ear, especially at the louder levels.

Designers can add additional speakers to create an even more immersive experience for players. Here’s Laura.

Laura: There are surround sound chairs where you have speakers mounted behind your head, built into the chair, and they also put a subwoofer into the seat...

[SFX: Slot machine with a punchy kick layered in]

Laura: So that's really going to give you a punch.

Laura also addressed a conspiracy theory that’s circulated through the slot machine world. This theory suggests that all slot machine music is actually composed in the same key.

Laura: No, it's not. I get asked that question a lot.

It's something that gets repeated because it's easy to understand. It's easy for media to say, "All slot machine music is in the key of C," without really explaining the history of whether that's true or not, and whether that's true today. It is most definitely, 100% not true today, because you've got your Kiss games, you've got your Michael Jackson games. You've got an entire James Bond series of games. Not all of that music is in the key of C.

The idea behind this theory is that music in the key of C evokes happy, upbeat feelings. And if you’re happy, you gamble more.

Laura: In the old days they were done in the key of C, as slot games have evolved, so has the music, so have the needs of the music.

[music in]

From the sound design, to the music, and even the placement of the speakers, its clear a lot of thought goes into creating the slot machine experience.

Laura: You're spending money to do this, so we want you to have a good time while you're spending your money. It's not because we're vultures and we want to take all your money. We're like anybody who sells something for entertainment purposes. We want you to have fun, because then you'll come back.

The sounds of slot machines are meant to get players excited and… hopefully come back for more. But what’s the science behind these sounds that keep us playing? We’ll get to that after the break.

[music out]


[music in]

A lot of artistry goes into designing slot machines… and also a lot of science. What is it about casino sound design that gets people hooked?

Karen: One of the first things you notice as you walk into a casino is just how much winning sounds are being played.

That’s Karen Collins. She’s an Associate Professor at the University of Waterloo. For the past 15 years her work has focused on sound and music in interactive media, and more recently, slot machines.

[music out]

Karen: Of course, they never have losing sounds [SFX: whomp whomp sound], so as soon as you walk in, you just hear the sound of people winning all the time, and it's, of course, very exciting, and it helps to draw your attraction to the machines thinking, "All of these people are winning. I can win too."

But of course, that’s not always the case. The idea isn’t just to keep the current player playing. It’s to attract others to play too.

Karen: "Wow, that person won a lot of money," but one of the tricky things we found with the machines is that it would play that winning sound even when you're not winning. So, if you placed a bet for, say, 50 cents, and you won 25 cents, well, you've actually lost 25 cents, but it would still play the music as if you had won. It makes you feel as if you're winning. So, even though you've lost, the machine's telling you that you've won.

But what does winning…or losing sound like?

Karen: They're using lots of bright, positive sounds. Lots of high frequency sounds. What we think of as sparkly or tinkly sounds. Lots of, we call it, audio bling.

[SFX: tinkly sound and sparkly sound]

But there’s more to it than whooshes and sparkle. Karen’s research found that cadence plays an important role as well.

Karen: Let's say we're having a conversation and I stop in the middle of a ... Right? You really want me to finish that phrase or that sentence. It feels unresolved, and the same thing happens musically in chord progressions.

[SFX: simple chord progression on piano, with resolution]

It generally moves towards what we call a resolution. What they do in slot machines is as you're building up ... Let's say you had five cherries that you had to line up, and it might go up in notes. "Doo doo doo doo doo." Then it would resolve. "Doo," and it feels good, but what they're doing in the slot machines is leaving it unresolved if you don't win.

[SFX: sample progression on piano, without final resolution chord]

So, that's why you want to bet again, you want to put some more money in, and then when you do win, you'll have that resolution and it's the sense of relief that comes along with it.

[SFX: final resolving chord from before]

It's playing on that part of our brain. "Hey, that feels good," and maybe we can't explain why it feels good, but it's all done in the music and sound effects there to trick you.

This concept isn’t anything new. In fact, music acting as a sort of trick goes all the way back to the original slot machines. They popped up around the 1890’s. At that time though, gambling machines were generally illegal.

[SFX: Old timey music]

Karen: So, what they would do in some of these machines would be they would add a musical component and call it a music box instead of a slot machine. So, the very first slot machines to have music actually were just ...It was just there so that they could get around the gambling laws.

Remember, this was a time before people had radios or even gramophones in their homes. It wasn’t that far fetched to go out to penny arcades and play these machines just to listen to music.

Karen: It wasn't out of place, but the idea was that you would put your nickel in and you would pull the lever to see if you won or not and it would play a little song [SFX: Old timey music]. But, because they weren’t really interested in actually playing music, sometimes the song would start halfway through the song or it would finish halfway into the song.

What started as a legal loophole became an important part of the slot machine experience. But today, slot machine music can still be viewed as more of a trick than innocent entertainment. It’s intentionally designed to draw you in and keep you in. And for some, it can be a truly addictive experience.

This idea is presented in a 1960 episode of The Twilight Zone. It’s called The Fever. In it, a character named Franklin goes to a casino and becomes obsessed with a slot machine.

[SFX: Clip from Twilight Zone: The Fever “She’s bound to… to turn up in a little while, you…”]

Karen: As he's playing, he talks about how the machine keeps calling out to him and mocking him and teasing him and beckoning him, and he talks about this idea of the losses disguised as wins and how it keeps luring you in through these little tricks.

[Clip from Twilight Zone: The Fever “Woman: Franklin Franklin: Eh?... What time is it Flora? Woman: It’s 8 o’clock…in the morning Franklin Franklin: I swear to you Flora, this machine mocks me, it teases, beckons. Put in 5, get back 4. Put in 6 get back 5. But, it’s got to pay off. Sooner or later it’s just got to I tell ya.”]

[music in]

Whether you think slot machines are a trick or entertainment depends largely on how you approach them. To Laura and Willie, the truth lies somewhere in between.

Willie: Personally, for me I can say, putting money into a slot machine, I want to win. I hope that I do win. But if I don't win, I also would love to have a great entertainment experience. That's what we're trying to bring to the new genre of slot machines, is the merging of the entertainment experience and the gambling experience.

Laura: If you think about Las Vegas and the strip in particular, you've got Caesar's Palace, and Treasure Island, and the Mirage, and New York, New York, all these themes, right? When you walk in there, they want you to walk into that world. They want to keep you engaged and happy so you don't go anywhere else. It's entertainment. It's, "Come to our place and have fun, and yes, we want you to spend your money here." Is that so bad? I think it's not.

[music out]

[music in]


Twenty Thousand Hertz is produced out of Defacto Sound. If you do creative work that also uses sound, head to defactosound dot com and reach out! We’d love to hear from you.

This episode was written and produced by Colby Hartburg… and me, Dallas Taylor. With help from Sam Schneble. It was edited, sound designed and mixed by Colin DeVarney. Thanks to our guests Laura Taylor, Willie Wilcox and Karen Collins.

The music in this episode is from our friends at Musicbed. And Musicbed wants to make sure you find the perfect song for your project. Not only do they have incredible browse and search tools, but they also have people on staff who are dedicated to helping you find the perfect song. At no extra charge they’ll send you suggestions based on what you’re looking for. Consider them another member of your team. Check it out a musicbed dot com.

I love hearing from our listeners. If you have a great show idea or want to give general feedback, head to 20k.org. There you can also read episode transcripts or buy a t-shirt or a stickers. Last, but certainly not least, we are a totally independent podcast and we have zero network support. So, our survival is completely in your hands. I know you love the show, if you didn’t there’s no way you’d be hearing my voice this late in the episode. Seriously, I see the stats, and not many people make it all the way here. So, it’s just you and me… and I need your help. I’m just asking for 15 to 20 seconds of your time. Please take that time right now to help spread the word.

Thanks for listening.

[music out]

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