I enjoyed wearing the Loop Experience earplugs. I did hear conversations and music through them well, but everything else sounded muffled and reduced. That means I wouldn’t feel safe going outside with these – I might miss important traffic sounds. But they provided me with some much-needed peace so I could work, effectively reducing the sound of the fan on my desk, as well as the construction noise that was going on across the street. An electric drill, a screaming infant, the relentless drip of a leaky tap. Some sounds are universally annoying. But for people with auditory sensitivities, sounds which many take for granted can be a source of irritation, distress and even pain. There hasn't been much research comparing different products and seeing which ones are most helpful," she explains, "And in the long term, whether they reduce stress. I think that's definitely a need that still exists."

I didn’t have a chance to try the Loop Experience at a concert – they’re sensory overload minefields for me – but I can imagine these would be firm winners for festivals and gigs. But a pipe like this doesn't transmit sound perfectly, so the output isn't the same as the input. "It's similar, but the natural resonances of the pipe will amplify sound at some frequencies and attenuate sound at other frequencies," Davies says. The pipe acts as an acoustic filter, which is the basis for wind musical instruments, and the thinking behind earplugs that claim to attenuate different sounds and frequencies. Traditional earplugs just fill the ear canal with foam to try to attenuate as much sound as possible," Davies says. "This is still the best and cheapest way to give the most attenuation with an earplug, but it works much better the higher the frequency." However, the earplug brands I’ve been testing made other adjustments to the design of the pipe, like changing its shape, filling it, adding extra pipes or adding material to it.The repeated claim that Calmer removes distortion isn’t a sensible way of summarising what the product does. I think it would be more accurate to say that Calmer reduces the level of mid- to high-frequency sound by a noticeable, but not a large, amount,” Davies says. Flare Audio's Calmer earplugs don’t look like regular earplugs. They’re small, made of soft silicone and have a big hole in the middle. There are specific instructions about how to fit these – they need to go into your ear canal at a certain angle – but they’re easy to follow, and this is a crucial step considering they work by ever-so-slightly changing the way your ear works. What we need is more research about the complex relationship between sound exposure and health outcomes, which is what Danielle Benesch, a Master's student working alongside Jérémie Voix at the École de Technologie Supérieure in Montreal, is interested in finding out. This graph has a rather sneaky linear frequency scale, so it looks mostly flat,” Davies says. “Replotting on a logarithmic frequency axis would be standard and would make it clear that the claimed attenuation is highest for 2-8kHz.” Low frequencies should actually be attenuated because often they are detrimental to your hearing and your intelligibility of speech,” Jérémie Voix says this is called low-frequency energetic masking. He explains that if you’re on the tube or metro and you’re having a conversation, it’s the low frequency that’s masking your speech.

Research like this is an essential step in learning more about individual hearing needs. It could also help to make more specific, personalised recommendations for certain audio sensitivity profiles in the future. They also, mostly, delivered on their promise of reducing some louder sounds whilst allowing me to hear others. This is vital if these are going to be worn for more extended periods and not prove to be prohibitive for socialising or staying safe. The Calmer earplugs by Flare Audio, for example, claim to “minimise stressful sounds”, allowing you to “focus on important ones.” The Vibes earplugs promise to “lower volume to more comfortable levels, while still allowing you to hear your environment with clarity.” Similarly, Loop says its Loop Experience earplugs are “for sensory overload” and “designed to take the edge off noise while keeping sound and speech clear.” And when you use the Knops earplugs, apparently, “real-world sound is filtered, the same quality is being kept and the volume is reduced.”At the first position, there’s no filter, which means you can hear as normal. At the second, some sound is reduced, the third reduces sound a little more, and the fourth creates a near-silent environment – well, depending on where you are and what’s around you. I wore them on the tube into central London and really liked being able to adjust the settings as I moved around – mostly switching between settings 2 and 3. However, the design of the dial does mean they’re bulky. Even with a snug fit in my ear, I was worried they’d fall out, which isn’t ideal for public transport. Davies tells me these earplugs are examples of passive acoustic filter design – passive means there's no active electronics on board. He explains these designs use the same principles as the silencer on a car exhaust in an old-fashioned car with a combustion engine.

This will give less attenuation than traditional foam plug but lets them design the filter shape to some extent," Davies says. This is how we get products that claim to reduce some sounds, but not all of them. However, Davies says "the exercise seems to be accompanied by variable amounts of pseudoscience and marketing guff." verifyErrors }}{{ message }}{{ /verifyErrors }}{{ So, how effective are the different pipe designs inside each of the earplugs? I asked Davies to comment on them, as well as Jérémie Voix, a professor at École de Technologie Supérieure in Montreal who leads the NSERC-EERS Industrial Research Chair in In-Ear Technologies (CRITIAS). Davies explains that the physical mechanism at work here is different to the other earplugs. “The Calmer alters the acoustic resonance of the ear canal (present in all typical ears) mainly by changing the shape of the airspace in the canal when inserted.” Although this design does work to attenuate some sound, we need to be wary of some assertions about these earplugs. However, Davies warns that the placebo effect might be at work in some cases, and believes all of these products need more sound attenuation tests to a recognised standard from a reputable lab.

How we tested

I was interested in whether I’d get the same reduction in noise with other high-fidelity earplugs or even foam earplugs with a hole in them. Voix tells me that, quite literally, putting most things in our ears would give us similar results – although I can’t speak to how comfortable they’d be. “Cigarette butts, and any of the passive filters you can see in the passive earplugs, will typically give you that same attenuation shape: a low-pass frequency filter that lets the low-frequency leak in, unfortunately.” Jérémie Voix says.