Why do we instinctively lower the volume of the radio when we're unsure of our direction?

Main Points

Back in 1930, the Radio Manufacturers Association argued that backseat passengers were more of a distraction than the car radio itself, claiming that listening to the radio was safer than glancing at the rearview mirror. Despite this, there was strong opposition to these claims, with many arguing that car radios were hazardous distractions. States like Illinois, Massachusetts, New York, New Jersey, and Ohio considered imposing fines for car radios, and in 1935, Connecticut even introduced a bill that would have fined $50 for radio installations — which would be roughly $1,100 today. Some even debated making the installation of radios a criminal offense [sources: Novak, Bureau of Labor Statistics].

It wasn't until 1939 that anyone conducted research to determine if car radios were linked to car crashes. The Princeton Radio Research Project concluded that car radios played no significant role in causing car accidents [source: Bijsterveld].

Years ago, the Society of Automotive Engineers suggested drivers follow the 15-second rule, meaning that in-car distractions such as talking to passengers or reaching for an item from the glove compartment could last up to 15 seconds before they became a visual distraction and unsafe. Imagine that: every 5 seconds at 55 mph (80 kph), a car covers 360 feet (107 meters), which is the length of a football field. Multiply that by three, and that's a lot of ground covered without the driver's focus on the road. Today, both the National Highway Traffic Safety Administration (NHTSA) and the U.S. Department of Transportation (DOT) recommend that no in-car activity take longer than two seconds before it becomes a distraction [sources: Parkview Trauma Centers, Barth].

Today, it's almost unthinkable for a new car to roll off the assembly line without at least a radio, if not a high-tech audio system. Car audio systems are now considered minor distractions (along with eating and drinking), contributing to one-third of the time we spend distracted behind the wheel. Texting while driving, however, is a much more serious threat, as it distracts a driver visually, physically, and cognitively all at once [sources: DMV, University of Groningen].

Although it's been long assumed that listening to music while driving is a distraction, studies have shown that merely listening — without interacting with the media player or adjusting the car's audio controls — actually challenges this belief. In fact, listening to music can help drivers remain focused during long trips on monotonous highways [source: University of Groningen]. But why, then, do we find ourselves adjusting the volume when approaching an exit or unfamiliar destinations? This stems from the demands placed on our concentration and the limitations of the human brain.

The Impact of Distracted Driving on Cognitive Function and Multitasking

When you’re lost or driving on unfamiliar roads, turning down the radio instead of relying on a map might feel unusual, but it’s actually a natural reaction from your brain to the situation.

To understand why you lower the volume on the radio when you’re lost, it’s important to understand the human brain. The brain consists of three main sections: the cerebrum, the largest part that controls higher cognitive functions like language and emotions; the cerebellum, which governs muscle movement and balance; and the brainstem, responsible for automatic bodily functions such as breathing, and for acting as a communication hub between the spinal cord and the cerebrum and cerebellum.

Throughout your day, you absorb information from your surroundings using your five primary senses: taste, hearing, smell, touch, and vision. Each sense has specialized neurons that inform the central nervous system about environmental changes. The brain, a key component of this system, processes this data and determines the appropriate response, a process known as encoding. The brain continuously assesses which task it should prioritize—the main task requiring focus—and which one should be secondary, receiving less attention.

The brain's capacity to switch between tasks is known as attention switching. However, this skill comes with a downside: while switching attention is fast, it isn’t instantaneous. Those brief moments spent toggling between tasks can slow down performance, leading to slight delays in reaction times. When you’re lost, these moments could make all the difference in whether you notice a crucial street sign.

Drivers often lower the radio volume when navigating busy urban streets, searching for a specific address, or driving in hazardous conditions like heavy rain or snowstorms. These situations demand more concentration than a routine drive, so turning off or lowering the radio clears up mental space, allowing the brain to focus on the most pressing task—finding the way.

The Limits of Human Sensory Perception: Facing the Music

At work, 11 percent of us jot down to-do lists during meetings, and more than half of us check our email while talking on the phone. Many of us pride ourselves on being expert multitaskers, believing that handling multiple tasks simultaneously or quickly switching between them is normal. But what you might not realize is that this so-called productivity isn't as effective as it seems. Despite our belief in our multitasking prowess, the brain isn't actually designed to handle multiple tasks at once [source: Faw, Sollisch].

The brain can easily manage a single task, but when given two, it divides its attention to tackle both. However, as more tasks are added, the brain's ability to focus effectively begins to decline. With divided attention, its performance suffers, leading to an increased likelihood of errors.

Our brains, despite their remarkable abilities, are not limitless in resources. They process tasks sequentially, switching between them so quickly that it appears as though multitasking is happening. Yet, because our capacity for attention and focus is finite, the brain must prioritize what to process. Multitasking, instead of increasing efficiency, results in competition for limited resources. This causes distractions, errors, and a reduced ability to retain information. Each task, fighting for the same mental space, slows down progress and often leads to mistakes, with performance suffering across the board. Multitasking can increase error rates by as much as 50%, and the time taken to complete tasks actually doubles, as we are not able to focus entirely on any one task. [source: Parrish]

When a third task is introduced, the brain's prefrontal cortex steps in to prioritize, discarding what it deems least important. This decision is made based on the limits of our sensory system, causing the brain to tune out less relevant information. For instance, when performing a challenging driving task like parallel parking, the brain minimizes distractions by blocking out background noise, narrowing the field of vision, and lowering the radio volume in order to focus entirely on the task at hand. [source: Telis]