A police officer once stopped Matthew Valbuena's deaf father because the stereo in his Benz was too loud. The system was hard to miss: four 12-inch subwoofers running more than 1500 watts of power. Valbuena's father could not hear the complaint, so the officer gestured for him to turn down the stereo. He understood, lowered the volume, and drove away with a warning.
That traffic stop captures a basic problem in designing in-vehicle technologies: sending a signal is not the same as communicating. A loud stereo, an unexplained dashboard beep, a flashing icon, and a hand gesture all depend on the occupant receiving and interpreting them correctly. If someone cannot hear the tone, cannot find the related message, or accidentally activates a control while using American Sign Language, the system has failed.
Sending a signal is not the same as communicating.
Valbuena's first language is American Sign Language, and growing up with deaf parents made him highly visual and perceptive. Today, as a Project Manager in Mazda North American Operations R&D, he works on infotainment, gauge clusters, head-up displays, controls, touchscreen icons, wording, and premium audio tuning. The practical standard is simple: every signal must make sense to the person receiving it, not merely to the engineer or designer who specified it.
When 1500 watts made music something his father could feel
Valbuena installed the four 12-inch subwoofers in his father's Benz. With more than 1500 watts driving them, the system made music physical as well as audible. It produced a bass response strong enough for his father to feel every note. The distinction matters because not everyone in a vehicle receives music, warnings, or feedback through the same sense.
Southern California car shows gave father and son a larger version of that experience. Car-audio companies brought high-output SPL demonstration vehicles fitted with multiple amplifiers and sometimes 10 or more 12-inch subwoofers. Valbuena's father could sit inside without hearing protection and still experience the system's physical force. Other visitors heard the output and protected their ears. He received it through the seat, body panels, and air moving inside the cabin.
Years later, that experience became relevant to premium audio tuning at Mazda. Mazda worked with Bose to develop BassMatch, an approach intended to let occupants feel the music when it is played at an enthusiastic volume level. The difference is immediate when the tuning works. A portable speaker can reproduce a track, but a well-tuned vehicle system adds controlled low-frequency energy that occupants can physically register without reducing the experience to loose panels and indiscriminate booming.
The Benz did not prove that more power automatically produces better sound. Four 12-inch subs and more than 1500 watts had a particular purpose for Valbuena's father: they translated part of the music into a form he could receive. That is a different design target from chasing volume. Sound, sight, and touch can support one another, but they are not interchangeable. Designers must consider and test each one separately.
American Sign Language became a foundation for interface design
American Sign Language made visual communication Valbuena's starting point rather than a later consideration. Long before he evaluated a Mazda user interface, he watched hands, facial expressions, position, and movement carry meaning. That background sharpened his eye for small discrepancies: a misaligned character, a crooked element, mismatched graphics, odd wording, or an icon that does not fit the rest of the display.
His career added practical experience to that visual foundation. He studied industrial design and initially wanted to design vehicles, but he had already begun installing car stereos at 13 years old. Professional installation taught him what must fit behind trim panels, under seats, inside dashboards, and within a real vehicle's electrical limits. Work at Pioneer Electronics then put him inside a Japanese electronics company before he moved to Mazda North American Operations R&D.
A vehicle interface is more than a single screen. Valbuena's remit includes the center infotainment display, digital gauge cluster, head-up display, buttons, controls, touchscreen icons, wording, and premium audio tuning. A direction, warning, or status change may appear in several places. If the icon differs between displays, the wording is unclear, or an element sits visibly out of line, the driver must spend attention resolving the inconsistency.
Valbuena compares the effect to speaking with someone who has food on their face. A person may follow the conversation, but the conspicuous detail keeps drawing the eye. Inside a moving vehicle, that distraction is more than decoration. The driver should be looking through the windshield, not wondering why a character is crooked or why an unfamiliar symbol has appeared in the gauge cluster.
A good dashboard does not constantly advertise the cleverness of its design. Its controls, touchscreen icons, gauge cluster, and head-up display should be understandable without forcing the driver to stop and decode them. When an interface feels seamless, someone usually found and corrected its awkward details before the vehicle reached the customer.
Why a dashboard beep cannot stand alone
Valbuena has little patience for a random beep. If the vehicle sounds an alert without displaying a clear visual cue, a deaf occupant receives no usable message. Even a hearing driver may notice the tone but fail to understand whether it concerns a door, a driver-assistance function, navigation, a phone connection, or another vehicle system. Noise is not an explanation.
Noise is not an explanation.
The fix sounds basic, but doing it properly takes coordination. An audible alert needs a related visual cue, and that cue must appear where the driver can reasonably find it. The wording or icon should identify what happened and, when action is required, what the driver should do. It must also remain visible long enough to be read. A message that disappears before the driver can safely glance at it is barely better than no message.
Designers must also decide whether the information belongs in the infotainment display, gauge cluster, head-up display, or some combination of them. Putting every warning everywhere creates another problem. Modern vehicles have an increasing number of safety and convenience technologies, each capable of requesting attention. Stack too many tones, symbols, animations, and messages together, and the driver begins dismissing them all as background interference.
Mazda's driving first position makes this a practical design constraint. Watching the road and controlling the vehicle remain the driver's primary tasks. An alert should interrupt only as much as its urgency requires. Its tone, visual message, location, duration, and required response must work as one communication sequence, rather than as separate features handled by separate teams.
Building in the visual cue from the beginning helps more than deaf occupants. Cabin noise, loud music, conversation, and uncertainty can make a tone easy to miss or misunderstand. An occupant should be able to mute an audio source, glance at the appropriate display when safe, and determine exactly what the vehicle is reporting. That is basic user experience work, not a finishing touch added after the warning logic is complete.
Gesture controls can mistake a family conversation for a command
Gesture operations pose a different problem because they can act on communication never intended for the vehicle. Valbuena's parents use their hands while traveling because they speak American Sign Language. A system watching for hand movements may not understand the difference between a deliberate vehicle command and an ordinary family conversation.
His example is specific: one occupant signs a question about where they should eat, and the vehicle interprets the movement as a request to raise the volume or start navigation. In the narrow technical sense, nothing has malfunctioned. The sensors may have detected precisely the movement they were programmed to detect. The failure comes from assigning command meaning to a gesture that belonged to a conversation.
A vehicle cabin is not a controlled demonstration space.
A polished demonstration can give a false impression of how well gesture operations work. During a demonstration, one person sits in a prepared position and performs an expected motion. In daily use, occupants reach for drinks, adjust clothing, point through windows, hand objects to one another, and communicate with their hands. Deaf occupants may do so continuously. A vehicle cabin is not a controlled demonstration space.
Valbuena's objection to gesture operation comes from watching his parents communicate, rather than from a blanket rejection of technology. He wants the system to confirm intent instead of inferring it. A physical button, rotary control, touchscreen icon, or well-designed voice assistant gives the occupant a more explicit way to request an action. Each method has limits, but the command is directed toward the vehicle rather than inferred from unrelated movement.
The same standard applies to CarPlay, Android Auto, and Google built-in in the new 2026 CX-5. Drivers expect in-vehicle technologies to perform tasks they already handle through phones and home voice assistants. Mazda must provide those functions while keeping the interaction suitable for driving. Valbuena puts the failure point plainly: if the driver grabs the smartphone, Mazda has lost. The alternative must be convenient, clear enough to trust, and controlled enough not to turn a signed conversation into an unintended command.
The lowered Toyota Pickup that led to Mazda R&D
Valbuena's interface work developed alongside his hands-on experience with cars. His first vehicle was a white-over-gray 1994 Toyota Pickup bought in 1996, before he had his license. The monthly payment was $163. He promptly lowered it, fitted aftermarket wheels, and built a substantial stereo system. Up front, he cranked down the torsion bars and flipped the ball joints. At the rear, he installed 4.5-inch pinion-corrected blocks and air shocks.
The truck kept changing along with his skills and tastes. A Clarion flip-out screen went into the dashboard, with a Nintendo 64 installed in the glovebox for use while the truck was stopped. Packaging audio equipment behind a standard cab's seat was a job in itself. The truck had roll-up windows, a bench seat, air conditioning, and only one side-view mirror on the driver's side, leaving little factory equipment to hide behind and not much spare cabin space.
After about five years of slowing down for speed bumps, Valbuena took the truck in the opposite direction. He lifted it, put it on 31s, added fiberglass fenders and exhaust, and left the last audio system in place. He owned the pickup from 1996 to 2002, then sold it to his father to fund the down payment on his second vehicle. The Toyota remains in the family, sitting in his father's driveway with its period modifications and Valbuena's CDs still in the changer.
Those CDs carried a practical burden of their own. His Case Logic wallet was designed for 64 CDs, but he doubled discs in the sleeves and carried about 100. At 15 bucks per store-bought disc, the wallet held $1,500 of music. Detachable faceplates, pull-out stereos, security systems with pagers, flip-down rear entertainment screens, amplifiers under seats, and CD changers were not historical curiosities to him. He installed and used them.
In August of 2002, he replaced the pickup with a 2003 Mazda Protege 5 in laser blue mica. The five-door hatch brought power windows, two side mirrors, factory keyless entry, power door locks, four-wheel disc brakes, and enough comfort for an approximately 46-mile one-way commute to Pioneer's offices in Long Beach. It became another audio build, with amplifiers under the front seats and various systems using two 12-inch subwoofers, later reduced to two 10s when cargo space mattered more. He kept the Protege 5 for about 11 years and has had a Mazda in the family since 2002.
At Mazda, that installation experience now meets the visual habits formed at home. Valbuena works across CarPlay, Android Auto, infotainment, digital gauge clusters, head-up displays, controls, touchscreen wording, and premium audio tuning. A specification sheet may separate these technologies, but occupants experience them together in one cabin. A poorly placed icon can draw attention from the road. An unexplained beep can exclude someone who cannot hear it. Uncontrolled gesture operations can misread American Sign Language. Weak audio tuning can remove the tactile bass response that lets an occupant feel the music.
The connection between his father's Benz and Mazda North American Operations R&D is unusually direct. The installer who used four 12-inch subwoofers and more than 1500 watts so his father could feel every note now helps determine how Mazda vehicles communicate through sight, sound, touch, and controls. His standard remains practical: tell the occupant what happened, show what action is needed, confirm deliberate commands, and keep the driver's attention on the road. That is what driving first requires if Mazda is to deliver what it calls joy from driving.
