I’ve visited Las Vegas only once in my life. I was there to speak to a gathering of rare book and manuscript librarians, a group generally known for its decorum. My hotel room looked out over the Strip and down upon a rooftop bar that pumped out window-rattling beats until the wee hours of the morning. At around 9am, I’d take the elevator down to the lobby, where I’d march through a miasma of second-hand smoke and breakfast beers, propelled by the peals and jangles of spangled slot machines. Those machines are designed, much like our pets, to compel us to keep feeding and touching them. And they know how to push our buttons, too: their celebratory songs elevate our excitement and confidence by sonically disguising even losses as wins.¹ After that obligatory trek through the casino, which tried so valiantly to entice me, I took another set of elevators up to the conference hall, where lots of leather bindings and tweed jackets dampened the polite hum. I breathed in a bouquet of catered coffee and old codices, then exhaled a sigh of relief.

The alleged sensory fraudulence of Las Vegas, that city-as-simulacrum, has been subjected to more than its fair share of opprobrium. Those who imagine themselves living in “authentic” environments, surrounded by organic, artisanal things, begrudge the city’s garish guile, its cunning use of spectacle and sensuality to induce consumption. Yet even the most minimalist, carefully curated environments are also sites of sensory engineering, where furnishings and gadgets construct hearing subjects and cultivate a habitus for particular behaviors and emotions. The reverberance of the glass house and marble hall, the sleek lines and soothing hum of a high-end refrigerator, the conversational protocols instilled by our voice-activated home consoles – all serve to discipline their human masters.

We rely on our gadgets, from tea kettles to Twitter, to signal their needs, to announce their approval of, or displeasure with, our actions, and to confirm that we’ve pressed the right buttons, that we’ve gotten the job done. Such concerns are particularly pertinent in this age of smart machines, typological novelties whose mechanical and computational operations are often imperceptible and unintelligible. In a modern world dampened by soundproofing, in a secular culture where few seek to discern the voice of God, these enchanted objects have become our frequent interlocutors.² We’d do well to consider how these resounding things are designed to interpellate, placate, motivate, even manipulate us – and, increasingly, to record and process the sounds we make, too.

CLUNK: Tools

Well before the rise of mini-transistors, integrated circuits, and piezoelectric speakers – which gave voice to our animated toys and greeting cards – craftspeople and engineers and manufacturers were creating objects that, either intentionally or incidentally, intoned a sense of accomplishment. They marked the completion of particular tasks, guided users’ productive activities, or triggered action in the social world. For thousands of years, bells have drawn communities together for celebration, mourning, and religious observance. Whistles have kept laboring and rowing bodies moving at pace and sent workers home after a day in the factory. Alarm clocks have roused those bodies from sleep.³ Many tools not expressly designed to resound have also long offered audible cues to skilled craftspeople: a good carpenter, for instance, knows when a hammer or wood plane is well deployed. Same for the axe and saw. The kettle, too. It’s worth noting that all of these sounding technologies make themselves audible and useful only for particular listening subjects and “able” bodies; a deaf worker, for instance, won’t hear the factory whistle, an atheist won’t proceed toward the church bells, and a royal most likely won’t rush to attend to a whistling tea kettle.⁴

Ubiquitous usability expert Donald Norman notes that sounding objects have long “convey[ed] a rich picture of the happenings around us…”

Many of our mechanical tools have been self-explanatory, offering insight into their function and cues for their use. The refrigerator hums, the fan whirrs, the washer sloshes and spins, the dryer rumbles, even the hard drive clicks. Such sounds, Norman says, “are natural: they were not added artificially into the system by a designer or engineer but are natural side-effects of the working of physical devices.”⁶ (As we’ll see later, though, even those “natural” sounds are often modified.) In such cases, we can observe – or imagine – our machines’ moving parts, hear the sounds of those parts moving, and assure ourselves that they’re working properly.

VROOM: Motors

Consider cars. In the early days of the automobile, motorists were commonly able to listen to their machines and diagnose defects. But then car manufacturers, responding to increased traffic din and the rise of noise abatement efforts, began prioritizing noise reduction.⁷ While loud vehicles once symbolized power and attracted admiring attention, they came instead to represent mechanical inefficiency.⁸ Similar shifts were happening in architecture, where new understandings of acoustics, new measurement and amplification instruments, and new building technologies began to divorce sound from environment – to engineer and universalize a normative, non-reverberant space.⁹ Car manufacturers likewise turned their attention to “silent” models with noiseless sprocket chains and closed-in, all-steel bodies, which eliminated squeaky joints. And they drew on new psychological testing regarding consumers’ attitudes about their automobiles’ sensory qualities.¹⁰

As Karin Bijsterveld describes, automobile advertisements of the 1920s and 30s featured car sound – the reassuring thud of a car door, or the cushioned cocoon of the interior – as a source of comfort, convenience, and safety.¹¹ While such promises appealed to both emotion and reason, they played down the fact that these new car designs were both enclosing and muting the car’s moving parts, thus diminishing drivers’ ability to listen to, and understand, their vehicles’ operation.¹²

Decades later, manufacturers introduced anti-lock brakes and other computerized systems for fuel injection, engine and climate control, and other self-diagnostic features. This operational “black boxing” – that is, the suppression of its internal complexity – further obfuscated and muted the car’s mechanics. All those “natural” sounds that Norman celebrates were further “hidden from sight and sound, taken over by silent, invisible electronics.”¹³ Simultaneously, Bijsterveld notes, we witnessed the rise of an “experience economy” and a demand for personalization, which necessitated a new means of marketing automobiles. Hence a growing focus on sound design beyond noise control.¹⁴

Those sounds that remain – the hum or an engine or the click of a car door – don’t merely denote functionality, efficiency and safety. They also connote particular affective qualities, signify specific brands, and target particular customers. Signals, wipers, horns, windows, door locks, and even the rustle of leather upholstery: all are subject to tuning by acoustical engineers. The discerning consumer can then distinguish the sound of a Maserati door from a that of a Mercedes or a Hyundai. At BMW, Jack Hitt reports, “maintaining consistent acoustic character throughout its fleet is an executive job description. BMW doors close with a clunk that must be in concert with the acoustics of the rest of the car, like the notes produced by the exhaust or the hum of the window motor.”¹⁵ In some models, the engine sound is piped in through the speakers; the possibilities for such audio-engineered enginery are wide open in the realm of electric and hybrid vehicles, which by Fall 2019 will be required by law to make noise at low speeds so as to alert pedestrians (and especially those who are visually impaired) of their presence.¹⁶

Harley Davidson has built its brand around (and attempted to trademark) a signature engine rumble – a gratuitous growl associated with freedom and adventure.¹⁷ Some resourceful consumers might choose to alter their vehicles’ acoustic signatures – making the engine sound louder or deeper, for example, by swapping out the muffler. Such acoustic modifications typically have socioeconomic, gendered, and cultural undertones, which are apparent in Formula One racing’s recent promise to increase the sound of its cars’ hybrid engines, as fans have requested.¹⁸ In some cases, though, such sonic enhancements are essential for drivers to be able to respond to their environment. Designers of smooth-riding, hermetically sealed cars, Norman said, have “had to work hard to reintroduce the outside environment in the form of ‘road feel’ to the driver through sound and vibration of the steering wheel.”¹⁹

Similar sonic attention has been paid to another high-performance vehicle: the vacuum cleaner. While we couldn’t imagine a Harley engine in a Hoover Conquest, many vacuum manufacturers do strive for some clamor, since noise connotes suction, strength, and control. In her study of vacuum advertisements across the decades, Anna Symanczyk discovered how those ads, in referencing sound, trained consumers to listen to and properly use their machines.²⁰ These conventions are gendered, cultural, and historical.

In the 1930s, for instance, when vacuums were marketed as feminine gadgets, manufacturers portrayed quiet machines that brought much-needed acoustic relief to the housewife’s family, who once had to suffer through mom’s intrusive ablutions. Later models marketed to men as high-performance gadgets emphasized their power and agility. In 2002 a duo of German engineers, drawing on psychoacoustic research, patented an acoustically enhanced vacuum design, with loudspeakers amplifying the sound of particles sucked into the machine: “the positive feedback about the process and progress of cleaning ‘rewards’ the user and increases his motivation. He gets the feedback that his work is worth doing and that he does a good job, since the dust flow is continually decreasing.”²¹ With the rise of bagless vacuums, consumers are less likely to have to listen for auditory cues that the bag is reaching capacity; they can instead see when the canister is full. Dyson introduced its first bagless model in 1983 – and while its early consumers tended to equate some noise with performance, the company has recently reengineered its fans and introduced sound-dampening mounts to make its products not only quieter, but also more pleasant-sounding.²² (As of September 2017, the European Union banned all vacuum cleaners louder than 80 decibels.²³ )

BEEP BURP: Household Appliances

Coffee makers – especially espresso machines – also tend to elicit acoustic tolerance. Despite their grinding and hissing, these machines usually generate positive emotional responses, in part because they ultimately produce addictive substances.²⁴ They foretell stimulation and indulgence (much like those slot machines we encountered earlier). What’s more, Elif Özan argues, when consumers perceive that a sound is utilitarian – that it serves a needed purpose, that it’s a product of carefully engineered parts – they perceive that sound as “functional” and thus tolerable, if not outright pleasant.²⁵ Yet when it comes to our stoves and refrigerators and dishwashers, appliances that stay “on” much longer than a coffee maker, we’d rather they not shriek and churn. However, these big metal boxes do provide auditory signals for the complex operations happening inside, and they summon us (particularly those of “us” who do most of the household chores) to action when necessary: “pay attention to me!”

“As appliances continue to move away from tactile buttons to touch-sensitive ones,” tech journalist Kyle Vanhemert writes, “electronic sounds are essential for giving us the feedback we need.”²⁶ “If I touch the interface and don’t feel or hear anything change,” musician/designer Aaron Day asks, “how will I know I have succeeded in doing what I wanted to do?”²⁷ As with automobiles, that feedback isn’t merely functional; it’s also affective. For example, General Electric distinguished its various appliance brands by creating a signature sonic “personality” for each.²⁸ The company’s designers wrote “soundtracks” for their Monogram, Café, GE, and Hot Point lines, then played with cadence, rhythm, and tone to derive beeps that denote “on,” “off,” “door ajar,” “finished,” and other key functions. The cake is done, the dishes are dry, the clothes are clean when the beeps tell us so.

Even the things we put in those big metal chirping boxes are sound-designed. In 1954, Earl S. Tupper received US Patent 2,695,645 for his “seal tight container” with the polyethylene “burping seal.” Commercials and product ambassadors showed housewives how to press down on the “magic button” at the center of the Tupperware lid to create an airtight seal, then to “wink” the lid’s edge to generate a tiny expulsion of air. That burp assured the conscientious housewife that she was protecting the freshness and quality of her family’s food and, at the same time, sought to evoke her motherly instincts, according to Alison Clarke.²⁹ In the 1970s, when a redesigned lid transformed the burp into a “whisper,” another company, Snapple, debuted with its own popping lid. By 2009, the beverage maker decided to eliminate the plastic shrink-band seal at the bottle-top, signaling that the lid pop itself was a sufficient guarantor of freshness and safety.³⁰

CRUNCH: Snacks

Snacks have also lent themselves to all kinds of orchestration. Researchers at Oxford’s Crossmodal Research Lab have found that potato chips like Pringles that are designed to make a loud, high-pitched crunch are “perceived to be a full fifteen percent fresher than….softer-sounding chips.”³¹ (Rice Krispies were probably born on a similar bet: that loud cereal sounds both fresher and more fun). Experimental psychologist Charles Spence, who runs the Oxford lab, has shown through hundreds of studies that our eating experiences are profoundly shaped by sight, touch, smell, and sound. When so much of our diet is derived from processed and packaged foods – and consumed in packaged environments – we rely on these sonic cues to fill in for a lack of “organic” signals of freshness and flavor.

Well-curated soundtracks in restaurants and on airplanes can boost taste sensitivity. And food packaging – color, texture, sound – can impact taste perception. Spence’s lab found that “altering the particular pitch and tonal quality of a beverage can’s opening hiss can make its contents seem fizzier or flatter, warmer or colder.” Sun Chips launched its own experiment: in 2010 they replaced their old, non-biodegradable polyethylene and polypropylene bags with new compostable bags made of plant-based material.³² Such eco-sensitivity was in keeping with the brand’s image, but it turned out that the chemical properties of the new packaging made it crackle. While crunchy bags might connote desirably fresh contents, in this case, the crunch was downright strident – around 95 decibels, the equivalent of a power mower.

Customers complained, sales fell, and Frito-Lay reverted to its old plastic packaging.³³ Recently, PepsiCo’s outgoing CEO Indra Nooyi suggested that Frito-Lay was still experimenting with its chip design. In an early 2018 interview, she proposed that women and men eat Dorito’s differently; women “don’t like to crunch too loudly in public,” and they don’t lick their fingers. She said the company was exploring “snacks for women that can be designed and packaged differently”; they’re low-crunch, less messy, and shaped to carry in a purse.³⁴ “Doritos, for Her” became the chip that launched a thousand jokes.

CLICK: Gadgets

Engineers and designers have tuned a whole host of domestic and beauty products. Method cleaners’ spray bottles, with their cleanly operating mechanisms; Axe deodorant’s canisters, with their powerful spray nozzles; Clinique’s High Impact Extreme Volume mascara tubes, which click crisply when they’re twisted shut; Vipp trash cans, whose onomatopoetic name references the sound of their sturdy lids: these engineered features signal cleanliness, strength, confidence, hygienicity, airtight containment.³⁵ And they signal to their target users that they’re doing it right: deploying the product correctly, storing it properly, getting the job done.

But what if there are no obvious moving parts? As we’ve swapped our mechanical tools for digital gadgets – many of which are tightly sealed typological novelties: slabs and towers and palantírs that veil their internal mechanical and computational operations – we’ve relied more and more on haptic and sonic cues to provide affirmative feedback. This richer mix of sensory signals has also created new opportunities for designers of assistive technologies.³⁶ Because our devices’ sonic cues typically signal the completion (or failure) of tasks the user has initiated herself, designer Max Lord proposes, there’s little ambiguity in their meaning – which “gives the designer great latitude in crafting these sounds, permitting creativity in expressing a product’s brand attributes” and its operating logics, too.³⁷

Consider some of these brand-defining orchestrations: In the mid-1990s, Microsoft asked Brian Eno to create “an entire company manifesto” – inspiring, universal, futuristic – “packed into the space of a boot screen.”³⁸ Around the same time, Jim Reekes created Apple’s iconic, and now trademarked, C-major Mac startup chord, intending for it to serve as a reassuring “palette cleanser” during reboots.³⁹

Yet sound designers faced a very different challenge only a decade earlier, as computers were rapidly entering homes and offices. Manufacturers had to acclimate users to new, virtual work environments, where there were fewer fluttering Filofaxes and screeching metal drawers. Most graphical user interfaces aimed to recreate the familiar desktop topography – of files and paperclips and trashcans – on-screen. Designer William Gaver, aware that users were already making sense of their machines through sound, by listening to their hard drives and printers, sought to develop a sonic counterpart to the GUI.⁴⁰ As an intern at Apple, he worked on an audio correlate to the Mac’s Finder file manager. His SonicFinder drew on analog references, like pouring water and shattering plates, to create a sonic index for digital actions (this work echoes the Foley tradition in film sound).⁴¹ Gaver’s taxonomy even accounted for different file sizes and types: the bigger the file, the lower the pitch.

While SonicFinder was never implemented, Apple and other tech companies continued prototyping sonic interfaces, some of which were gratuitously skeuomorphic, with clicks and scrapes for every tick, scroll, and drag. Jim McKee said his own proposed Mac audio palettes were supposed to “add texture to the UI, more than sound… It made you feel like you were actually touching things and moving things.”⁴² But when Steve Jobs returned to Apple in 1997, he shut down the project, allegedly proclaiming, “Nobody wants sound coming out of their computers” (perhaps it’s no surprise that, twenty years later, Apple ditched the earphone jack on the iPhone 7).

Contemporary digital designers are continuing in Gaver’s tradition, creating “earcons” and “auditory icons” that both direct user interaction and cultivate character.⁴⁰ Apple created VoiceOver, a gesture-based screen reader that helps visually impaired users navigate the screen, read text, track battery status, and so forth. Spotify created cues for its audio controls – pausing, playing, skipping tracks – that “help the user understand that they made the correct (or incorrect) interaction.”⁴⁴ And those sounds bear some indexical relation to their analog analogues: pausing, for instance, is signaled by a series of descending beeps, which connote “powering down.” Roman Mars, host of the 99% Invisible podcast, proposes that when sound design is done right, “electronic things feel mechanical; it’s the feeling of movement, texture, and articulation where none exists.”⁴⁵ We hear this with the iPhone, which is set by default to emit tinny typewriter-y clicks when we peck on its keypad, and its camera, which registers each shot with a modified shutter sound – somewhere in-between a skeuomorphic reference to an analog shutter and a born-digital beep.⁴⁶ When we empty the trash on a Mac, we hear that cathartic crunch.

McKee notes that users tend to like both the trash crunch and the “send mail” whoosh. “It’s a redundant thing,” he said. “They end up liking it because it gives you that feedback that ‘Yes, you’ve done something.’”⁴⁷ You’ve cleaned up your virtual workspace; you’ve crossed an item off your to-do list. Those sounds that signal new tasks – the incoming mail ding, the voice-mail beep – are, not surprisingly, less popular. Excessive dings and beeps and clicks often cause annoyance and promote desensitization, which is why many people turn off the keypad clicks and alert notifications on their iPhones. (We see parallel effects on construction sites, in hospitals, and in mines, where workers exposed to constant rings experience “alarm fatigue,” which risks numbing them to the presence of real dangers and emergencies.)

And as we’ve seen in numerous previous examples, these sounds signal more than a “job well done”; they also cultivate affective experiences. Skype, for instance, wanted users to associate the platform with cleanliness and optimism, and they aimed to create a sonic interface that feels “as natural as answering an old phone” – as if the interaction is an “intimate, unobtrusive extension of the person at the other end of the line.”⁴⁸ So they worked first with Soundtree Music, and later with the Listen branding agency, to build a palette (much like Gaver’s) from organic sounds like wind, water, bubbles, and human voices, which they then layered (à la musique concrete) to create “something abstract but acoustically natural.” The five-beat incoming-call sound, for example, is a mix of human breath, voice, and water. It’s meant to be un-hummable, forgettable, just as the platform aims to efface itself in connecting human voices.

Listen later worked with Tinder, the dating app, to orchestrate its sonic identity and improve user experience. Sonic notifications were meant to signal not completion, as is common with other app earcons, but “optimism and possibility.”⁴⁹ They sought to convey three paired qualities: lightheartedness and fun were expressed through “major modalities and playful melodies with lightly plucked instruments”; surprise and delight were embodied in “quick tempos with percussive, bright, and resonant tones”; and freshness and youth came through in the sound’s snappy “game-like feel” (game sound design is an expansive terrain we don’t have time to explore here). The app thus makes clear who it’s targeting, and it sonically signals the nature of contemporary dating: it’s a game for the quick and nimble.

HELLO: Voice-activation

Today, as we’re maxing out the capacity of our visual displays – and as our screens shrink and our interfaces become “ambient” – interaction designers are turning more often to sound, and particularly to voice-activation.⁵⁰ When our vision is “already occupied by other, high-priority tasks, such as observing the street while driving a car, or watching TV in the ‘smart home,’” Daniel Hug proposes, sonic interfaces allow for “eyes-free” interaction, for an escape from the “tyranny of the screen.”⁵¹ Sound, Amber Case and Aaron Day proclaim, “eases cognitive burdens.”⁵² Again, this is particularly useful for the visually impaired.

Many of our new “smart” gadgets, like Siri and Alexa, strive to speak our language and model our mental processes. Prompting particular forms of verbal input, these assistants help us help them help us get stuff done – whether ordering a pizza and checking the weather. New “hearables,” in-ear devices, can beam the voices of artificially-intelligent personal trainers straight to our inner-ears. When we’re out for a jog, we can choose whether we want that motivating voice to be ruthless or nurturing. Sound sets rhythms and, as many laborers have known from years on the factory floor and in the fields, impacts productivity.

Yet Alexa, in training us to speak her chatbot patois, also conditions us to unwittingly open up our homes and our lives to eavesdropping. While she helps us to complete simple tasks and whittle down our to-do lists – to be productive – we also practice a passive productivity as data-bodies: as sources of psychographic and behavioral information for advertisers and monitoring agencies. Sapna Maheshwari notes that Amazon and Google, makers of Alexa and Google Home, have submitted patent applications describing “voice-sniffer algorithms” and technology that listens for elevated voices and sneezes to assess users’ mood and health.⁵³ Both companies have hazy policies regarding the sharing of consumer data and voice transcripts. These features allow tech companies to transform our voices into doubly-productive apparatae, both aiding in our own chores and, at the same time, making money for Amazon.

Meanwhile, in the digital workplace, where our symbolic labor offers few material signs of its impact (or even its existence), we increasingly turn to pings and pops to provide periodic confirmation of our accomplishments, to reaffirm our identities as diligent, competent workers. Those bells and beeps offer validation or reassurance as often as we need it – which, in this age of the constant status update and continual refresh, is fairly often.

In a larger ecosystem fed on processed foods and plastic, circulating within an economy powered by nano-scale chips and planetary-scale infrastructures, we can’t rely on empirical, “organic” cues regarding the safety and security and operability of the things we consume. So, we entrust crinkly bags to verify that our snacks are fresh, amplified engines to warn that a car is fast approaching, “earcons” to confirm that those bits constituting an email message were just successfully sent across the ocean via transoceanic cable. These are the sonic markers of accomplishment in an age of geoengineering, genetic modification, blockchains, and quantum computing – realms whose own frequencies of communication are often outside the range of human hearing.

As we move into an artificially intelligent world whose logics of operation often exceed our own understanding, perhaps we should linger a bit longer on those blips and clicks. Compressed within the beep is a whole symphony of historical resonances, socio-technical rhythms, political timbres, and cultural harmonies. Rather than simply signaling completion, marking a job done right, a beep instead intones the complex nature of our relationships to technology — and the material world more generally.