Comment & Analysis: The problem with common sense is that its not all that common. This is not something I thought Id ever write, but Voltaire, the 18th-century French philosopher, offers a good starting point for thinking about cycling and headphones or earphones.Before getting too deep into philosophy, were talking about this (again) because the chairperson of Irelands parliamentary Committee on Transport, Michael Murphy, a Fine Gael TD, posted a video on social media asking whether cyclists should wear headphones or earphones.Some modern-day philosophers have since pondered why Deputy Murphy is zooming in on one of the age-old cycling questions at a time when road deaths are spiking again, and theres no link between that trend and people cycling while listening to The Last Word, The Hard Shoulder, or Drivetime.I dont think I ever read anything directly from Voltaire before (even if translated). Its actually quite enlightening (excuse the pun). In Dictionnaire philosophique (1765), Voltaire grapples with the idea that common sense is not that common at all. Today we not only still think common sense is common, but we also think our senses are common. We think what we experience with our senses is a common experience. Of course, it is common to a degree, but to another it is not. When deaf people exist and some of them cycle, its clearly flawed reasoning to assume we all hear, see, perceive, and react to things the same way.Its like bike mirrors and how evangelical their advocates are when most people are fine with a shoulder check. Different things suit different people, or the same people at different stages in their lives. And this all applies to the thorny issue of cycling while listening to music, the radio, podcasts, or audiobooks using headphones or earphones.Ive read and have been involved in debates about this over the years, and I find it hard to reconcile the set-in-stone view (including from some cyclists) that audio gear should never be worn and then how (1) so few scenarios there actually are in most peoples daily or weekly cycling where normal volume audio cues would help much espcally in busy urban ebviormnets when theres a stream of motorists, and (2) that these people cannot get over the idea that just because you have headphones (one ear or two) it does not mean you cannot hear anything.Even in cases where you want to hear whats coming behind you on bendy rural roads or in other contexts, often theres very little that can be done when such roads are narrow and lined with dense greenery on both sides. You could maybe shout out and hope the cars soundproofing isnt too good, or that they dont also have their radio cranked up to the last.And even if youre listening to the radio while cycling along, that doesnt mean you wont hear a motorist flying around the corner behind you. Or, you know, you can turn it off when you need to hear better.In Ireland, even beyond this debate, some eagle-eyed cyclists and others have started to notice that more and more motorists seem to be wearing AirPods-like earbuds while driving. Its unclear why maybe bypassing their convoluted or broken built-in hands-free? Any ear blockage motorists have is on top of improved sound insulation in cars.As pointed out in Saturdays article, one experiment found that people cycling with earbuds playing music at a reasonable volume hear much more outside noise than a car driver, even when that driver has no music playing. One response is that its more important for cyclists to hear things, with some thinking motorists only need to hear car horns or emergency-service sirens. But why do some people think thats true?Ive had good reason to shout at both motorists and cyclists to get them to stop or slow down to avoid people on foot or bikes (including myself). The most recent example was a cyclist coming around a blind corner on a footpath, but I can think of far more times Ive had to do it to motorists, maybe most often when they have misjudged overtakes.I also have a loud bell that motorists can hear if their window is down, or if their music or the surrounding traffic noise isnt too loud. With those things combined, Im somewhat puzzled why some people think motorists being able to hear isnt important. For the record: My default is one ear only. Except in very limited cases, such as using earbuds to block out the noise of a busy national road for a short time on a greenway running too close to it in a remote area with no junctions, I cannot remember the last time I wore earbuds in both ears. Usually I have the right-hand side in. I could rationalise this and say its partly because the left side is closer to where motorists or passengers will open a car door, or a pedestrian will step out. But the truth likely is, my right earbud has the stop/pause function, and having access to that matters more to me than any of those factors.My rule is not my own; its one I picked up. The one-ear rule is also enshrined in law in most jurisdictions where laws have been set about this mainly US States and a number of counties. Some EU countries like France and Spain have a total ban, but its important to say that at least in some of the countries where such a ban is in place, it seems to be a catch-all rule that includes motorists.I dont exactly know when I started with the one-ear rule. Maybe I learned my lesson after trying earphones in two ears at once and realised I couldnt hear as much as I would like? I dont know. I regularly wore wired earphones in one ear before earbuds were popularised so, it was decades ago; I cannot recall, to be honest.But I know there are views beyond my own.At one end of the scale, some people think its daft that anybody would ever consider cycling with any ear coverings (maybe ear muffs or hats in the winter included?) some speak from the experience of cycling, and others from the point of view of never having cycled, or at least not for decades.At the other end of the scale, some people say they can wear over-ear headphones or two earbuds with no issue.There are also deaf cyclists, and others, including those who are neurodivergent, who use headphones to avoid sensory overload from the noise of cars, vans, buses, and trucks. Our senses are not common, so people need to stop thinking its common sense to think they are.Just like most people adapt to cycling without mirrors, most people who want to listen to a podcast when cycling to work will account for being able to also hear whats around them. Of course some people wont, but these are the people who wont take a blind bit of head to the law one way or another.Our laws are not always rationalAs well as common sense differing between groups of people, the notion that it could never be safe to listen to any music or audio when cycling and so it should rationally be banned dismisses the fact that our laws on distracted driving are not rational. As covered in Saturdays article, Gemma Briggs, an applied cognitive psychologist with a specific interest in attention and perception,wrote in a 2022 article that:Decades of research has demonstrated drivers on the phone arefour timesmore likely to be involved in an accident than undistracted drivers, regardless of whether theyre using a hand-held or hands-free system. This increased risk lasts for aroundfive minutesafter the call has ended, suggesting that interacting with the technology isnt the only issue. It seems that phone conversations take the drivers focus away from their primary task of driving, even after theyve hung up. People are largely unaware that their minds wander like this, or that it can affect their driving.In those decades, distracted driving has increased due to the illegal use of messaging while holding phones and the lesser-talked-about issues of people watching videos while in heavy traffic, and the legal use of touchscreen controls in cars (widely rolled out for well over a decade before the trend was acknowledged widely as a safety issue).But while little is being done to address our modern distractions, nearly nothing has been done to even tell people that hands-free calling when driving is risky. Theres not even basic advice that driving isnt the time or place for full-blown conversations over the phone.Meanwhile, for most cyclists, there arent many scenarios where reacting to ambient sound will prevent a crash, yet the moral panic around cyclists keeps setting in headphones are just this weeks topic.