The excitement around hearables is currently driven by true wireless stereo (TWS) devices. Sales of TWS are growing rapidly, even amid the pandemic, and the number of brands and models jumping on the bandwagon is also growing at a fast clip. However, there are other devices out there that warrant attention, such as the subject of this review – the Aftershokz Aeropex.

All of Aftershokz products are based on the idea of bone conduction. This is the almost magical ability to apply vibrations to the bones of the head (typically the temporal bones), which directly interact with your inner ear to generate sound, bypassing the outer ear, including the eardrum, entirely. However, this means the outer ear is still open and can hear ambient sounds as well. This creates the distinctive advantage of the open-ear design of bone conduction headphones. But are they worth buying?

History and Uses

Bone conduction is not a new concept – it was the basis for enhancing sound among those with hearing loss for decades before the invention of the electronic hearing aid. I first tried Aftershokz products almost a decade ago at a sporting goods convention.

The Aeropex is the latest in a long line of Aftershokz products, indeed the first set I possessed used a 3.5mm jack plug. All but one of Aftershokz line-up are now Bluetooth. The exception is the Xtrainerz model which stores up to 4GB of MP3 audio locally to allow for use while swimming. All others receive Bluetooth signals from paired devices – typically a smartphone.

The Aeropex are extremely lightweight – 26g (around an ounce) – and wrap around your head and arch over the ears to place the transducers on your cheek bones. In use, they are extremely comfortable – much more so for me than in-ear TWS or wired ear buds, which I find irritating and all too liable to fall out. I often forget I am wearing them, and find them on my head hours after turning off music or other audio. I sometimes wear glasses too, and this presents little problem - the arms of the glasses lay over the top of the arms of the headset and, if anything, slightly enhance the sound transfer. The only comfort issue is if using them while sitting in a chair with a headrest because the wrap around band can push the transducers off your cheek bones. However it's usually possible to find a way to position the band so this doesn't happen.

The main purpose for wanting to use bone conducting, open-ear, Aftershokz headphones is for running. I run quite a bit. Sometimes near to or on roads, but mostly on trails. While running on roads I need to be aware of traffic. And on trails, I love to hear the sounds of nature, and other trail users, such as bikers, are much less likely to take me by surprise.

So How Do The Aeropex Sound?

These are the third generation of Aftershokz headphones I’ve used. After the wired ones, I got a pair of the company’s Trekz Titanium, which were good, but the Aeropex are much better. The sound is not going to rival over-the-ear headphones such as my Bose QC35 or Sony WH-1000XM3. But I find them better and more comfortable than either my Jabra T65 Elite Sport or first generation Apple Airpods. I think with my Jabra earbuds, I cannot get a good fit despite trying multiple variations of tips and wings. This means sound leaks leading to a relatively tinny audio reproduction.

While the Aftershokz Aeropex are not going to win awards for stunning high fidelity because the bone conduction process tends to lose bass frequencies, the sound is much better than you would expect. And you can enjoy the marvellous experience of listening to Vaughn William’s Lark Ascending, while simultaneously listening to actual skylarks trilling high in the sky. Mid-range frequencies are faithfully reproduced and the sound is well-modulated with vocals having a warmth that belies the lack of deep bass. Drums and treble frequencies are decently crisp. And the Aeropex do a much better job of isolating the feeling of vibrations on the cheek bones that was noticeable with the Trekz Titanium – especially at higher volumes.

However, although I do use the Aeropex for music, I mainly use them to listen to audiobooks and podcasts. They are perfect for this and I am able to consume mountains of books and hours of podcasts while out running in the hills.

They have dual noise-cancelling mics that allow for good voice calls; the other party unaware that I am using anything out of the ordinary to conduct the call.

In terms of volume, it is possible to have volume quite loud – loud enough to obliterate most ambient sound. I tend to find myself opting for a mid-level volume that provides a good balance between clearly hearing the audio feed while still being able to hear ambient sound. An example from a recent run. I was jogging down a trail listening to a podcast. I heard a quiet crunch of gravel and turned to see a mountain biker approaching from behind me. Had I been wearing TWS, I would likely have been completely unaware he was there. This ability to hear what is going on around you is important. In many athletic events, participants are not allowed to use earphones and face disqualification if they do; the reasoning being that they will not be able to hear instructions given by marshals. However, open ear designs, like the Aftershokz Aeropex, are allowed.

At medium volume there is not much sound leakage, but at higher volumes people sitting nearby in a quiet environment may be able to hear some sound from the transducers.

Long Battery Life

On more practical matters, the lithium polymer battery is rated for eight hours continuous playback. I have not timed it but it does last well. Charging via a magnetic induction cable is easy and while not swift at two hours, is fine for charging overnight, which is what I typically do. The headphones are IP67 rated, so will withstand a drenching and even immersion in water, but the Bluetooth connection will not penetrate into H2O, so they’re not suitable for use while swimming - the Xtrainerz model is designed for that.

The controls are fairly minimal. The power button serves to raise volume and, if held for several seconds, will induce the pairing mode. There is an adjacent volume-lowering button. On the outer surface of the left transducer is a button that functions to pause/restart/skip. The simplicity of the design means the controls are easy to learn; I find the controls on my Jabra confusing and often need to take them out of my ears to look at the markings on the tiny buttons.

Conclusion: Niche Uses and Niche Pricing

Aeropex is Aftershok’s top-of-the-range model and costs around $160, which is relatively expensive compared to many TWS products. Other bone conduction models with a similar-looking design are available from other brands, and many are considerably cheaper. However, I have not had the chance to use them, so can’t comment on their quality.

In summary, I am a fan of the Aftershokz Aeropex and have recommended them to many people. But with caveats. If you’re a runner or need a hearable where you also need to hear what’s going on around you for whatever reason - for example in a work situation, then the Aeropex should be considered. In this context, they're excellent and provide a good overall experience. But for audiophiles or for users who don't need to hear ambient sound, other options may be preferable.

More and more TWS now offer active sound management - for example, noise cancellation and the ability to pass through sound from the environment. These reduce the distinct advantage of the open-ear design, but there remains a big difference between the ability to truly hear what is going on around you and the sound that is filtered through the digital signal processor in a pair of TWS ear buds.