Fauna Audio Spiro Transparent Brown Sunglasses review

Comfortable unisex shades with taps, slides and discreet audio fit for podcasts and making calls

Fauna Audio Spiro Transparent Brown Sunglasses
(Image: © Jamie Carter)

TechRadar Verdict

Well designed with discreet speakers and some excellent tap and slide touch controls, these Bluetooth-enabled speaker-sunglasses succeed on style, comfort and ease of use. The audio is always clear, but it lacks enough bass response for music.


  • +

    Clear sound

  • +

    Easy to use touch interface

  • +

    High-quality lenses

  • +

    Excellent USB-C charging case

  • +

    Integrates with voice assistants


  • -

    Lacks bass response

  • -

    Low maximum volume

  • -

    Four-hour battery life

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Two-minute review

Need some Bluetooth-enabled speaker-sunglasses for the summer? These competitors to the Bose Frames succeed on comfort and convenience, but don’t quite match the bigger brand on sound quality.

‘Open audio’ is the future. The ability to go for a walk or run without having to block out everything happening around you is safer and more pleasant than being locked away in your own head. Open audio is exactly what Fauna Audio’s Spiro Transparent Brown sunglasses offer inside a subtle, stylish and discrete unisex package that cleverly hides its core technology.

There’s no way anyone walking past you in the park is going to know your temples are kitted-out with a couple of microspeakers, a woofer and a microphone. Nor is anyone going to notice when you double-tap the arms to skip a track or slide a finger down the arm to increase the volume.

Fauna Audio Spiro Transparent Brown Sunglasses

(Image credit: Jamie Carter)

Trouble is, the volume doesn’t go high enough to drown-out ambient noises while the sound quality – though incredibly clear and precise – doesn’t do much of a job with music. They work great for listening to podcasts and talk radio, and they’re excellent for making hands-free calls. But they don’t have enough bass response for music.

So despite being much better as a wearable device and as a pair of sunglasses when compared to the Bose Frames, they don’t sound quite as good.

Where the Spiro Transparent Brown sunglasses does get one-up on its rival is on longevity. Though they boast a 4-hour battery life it ships with an excellent sunglasses case that’s able to refuel them at least four times over.

It all leaves us thinking that while open audio remains the future, that future isn’t quite here yet. The Spiro Transparent Brown sunglasses impress, but overall they leave us still waiting for audio eyewear’s breakthrough moment.

Price and release date

  • On sale now
  • Cost $299 / £249 / AU$449

You can buy the Spiro Transparent Brown sunglasses around the world now from Look Again and wearfauna.com.

Fauna Audio’s ‘smart glasses’ come in four frame designs and colors: the unisex Spiro Transparent Brown model we have on test here, the feminine Levia Black and the Havana-design Memor Havana (both of which use blue light filter ZEISS DuraVision BlueProtect lenses), and the semi-transparent Fabula Crystal Brown.

All are the same price in all market, but it’s worth knowing that at the time of writing they were slightly more expensive than Bose Frames.


  • Excellent charging case
  • Tinted Carl Zeiss lenses

The Spiro Transparent Brown look like designer sunglasses. Their tint is graded and reduces to almost nothing lower on the lenses. The only hint that they are also an audio device are slightly bulky arms, which is where the micro-speakers and other tech are housed. That includes a 100 mAh battery, two microphones (complete with beam-forming and echo-cancelling), those four microspeakers positioned just beside the wearer’s temples, two woofers, and the Bluetooth 5.0 circuitry.

As for the glasses themselves, they feature tinted Carl Zeiss lenses 1.8 mm thick that offer 99% protection from UVA and UVB.

Fauna Audio Spiro Transparent Brown Sunglasses

(Image credit: Jamie Carter)

They’re cable-free thanks to a clever charging case, which weighs 190g and measures 169 x 57 x 66 mm. It features a USB-C slot for topping-up its built-in 1,300 mAh battery alongside four green LED lights that indicate how much power is left in the case.

As you fold up the glasses to place them in this charging case you’ll reveal charging contacts in the hinges between the arms and the lenses. As you place the sunglasses in the charging cases these make contact with charging contacts in the case and your sunglasses automatically recharge. A short orange USB-C cable is included in the box along with a small microfiber cleaning cloth.

The Spiro Transparent Brown weigh around 50g (that’s about the same as the Bose Frames) and measure 145.5 x 46.5 x 153.5 mm. They’re not heavy to wear, but they do feel noticeably heavier than regular sunglasses.

They’re water and dust resistant (to meet the IP52 specification), which means you can wear them in drizzle and they’ll also take some sweat. So you can go for a run in them, which is a good reason for purchasing them; as well as offering cable-free music and awareness of what’s going on around you the Sprio didn’t move around much during our test.


  • Easy to use tap and slide touch controls
  • Bluetooth 5.0 pairing is instant after the initial setup

Although they arrived with some charge in them, it’s necessary to remove a couple of safety stickers over the glasses’ charging contacts. Then you can charge-up the case and the glasses, which takes a couple of hours from empty. The outermost green LED lights switch on if you’ve positioned them correctly (though it’s hard not to).

Once refuelled, open the charging case and the green LEDs blink on and the glasses audibly declare 'Fauna is on, Fauna is pairing'. On first set-up, the user is directed to flash a smartphone’s camera at the QR code in the charging case, which takes you two a support page on Fauna Audio’s website. There’s a four-minute YouTube video tutorial and some user guides to download.

There are also instructions on there for opticians so you can have them heat-up the Spiro Transparent Brown sunglasses’ natural acetate material and swap-in some prescription lenses.

Fauna Audio Spiro Transparent Brown Sunglasses

(Image credit: Jamie Carter)

Before you get through all of that you’ll get an audible 'try pairing again' message, and in our test, we just couldn’t find the glasses in our smartphone's Bluetooth menu. This is where it pays to watch the video because it explains, right at the end, that a four-second tap-and-hold on the right-hand temple force-pairs the glasses.

So it proved, and once paired they stayed connected, and reconnected automatically thereafter. It’s possible to pair them to several devices, though only one device can be linked at any one time.

There are plenty of other easy to use touch controls. Capacitive touchpads on each arm allow a number of taps and swipes that differ on each side. On the left side, a double-tap starts and pauses music or accept/ends a phone call, a slide back and forth adjusts volume, while a four-second tap-and-hold either skips a track or rejects a call. Meanwhile, a double-tap on the right side activates your phone’s personal assistant.

Fauna Audio Spiro Transparent Brown Sunglasses

(Image credit: Jamie Carter)

These commands work well largely because they’re very simple and the arms are plenty touch-sensitive enough. So much so that while removing them from your head it’s easy to wake up Siri et al.

We didn’t encounter any connection problems during our test, though we did notice that these sunglasses lack an off switch. The upshot is that while it’s easy to wear them on your face for a few hours, if you sit down for a coffee and want to deactivate them you have to switch off the music on your phone and/or put them back in their charging case. They do go into standby after about 20 minutes, but with such a short battery life that’s a significant amount of wasted time.

Audio quality

  • Clear sound quality
  • Lacks bass response for music

The key tech inside the Spiro Transparent Brown sunglasses is a set of MEMS electrodynamic microspeakers, which are the brainchild of Fauna Audio’s parent company USound. Each brace of microspeakers comes with a woofer.

Let’s begin with a consideration of why the ‘open audio’ concept behind the Spiro Transparent Brown sunglasses is perfect for being out and about – particularly in urban areas. If you’re moving around a city, it’s not a good idea to wear earphones that block out all ambient sound, tempting though that is. That goes double if you’re going for a run, where pedestrians and vehicles can appear out of nowhere.

Although they make it possible to listen to music or talk without blocking the outside world, what we liked most about the Spiro Transparent Brown sunglasses is their clarity. With a podcast playing, or while talking to someone hands-free on the phone, the sound quality is excellent – clear and precise – and the microphones in the glasses’ right-hand side (both equipped with beam-forming and echo cancelling) appear to work well.

Fauna Audio Spiro Transparent Brown Sunglasses

(Image credit: Jamie Carter)

What its microspeakers lack, however, is much ability with the width and depth of music. The mid-range is thin and the low-frequency sounds are discernible, but only just. Put simply, they need more bass response. Having said that, it’s all very listenable and there’s a fine sense of stereo separation, but that lack of bass leaves them short of the audio quality offered by the Bose Frames.

There’s also an issue with volume, particularly if you use the Spiro Transparent Brown sunglasses in a city. While they work well for a walk or jog around quiet suburban streets or in a park, you’ll struggle to hear everything while crossing busy roads. However, rather surprisingly there’s also very little leakage, so unless you’re in a quiet place indoors with the volume on maximum no-one is going to hear noises coming from your sunglasses.

Fauna Audio Spiro Transparent Brown Sunglasses

(Image credit: Jamie Carter)

So while they do supply clear and highly listenable audio, they’re at their best with podcasts and talk radio, and for voice calls, but don’t impress for much more than background music.

Battery life

  • Four-hour battery life
  • Charging case refuels four times over

The clever, surprisingly svelte design of the Spiro Transparent Brown sunglasses comes at the cost of disappointing battery life. Although they have a life of 20 hours in standby mode, in actual use playing music or making calls they last for about four hours. Par for the course in the audio sunglasses niche, perhaps, but limiting nonetheless.

The saviour is an excellent charging case, whose 1,300 mAh replenishes the Spiro Transparent Brown Sunglasses’ built-in 100 mAh battery four to five times over.

However, the necessity to take the case everywhere is a little limiting. It should be possible to wear any pair of sunglasses for a whole day without having to think about their battery life.

First reviewed March 2021

Buy it if

You listen to a lot of podcasts
The MEMS electrodynamic microspeakers inside the sunglasses’ arms supply your ears with very clear and precise directional audio that works best with voice. Perfect if you mainly listen to podcasts and/or make a lot of hands-free calls.

You hate charging cables
An excellent charging case gives you somewhere to safely stow the sunglasses, but can also replenish their 4-hour battery life at least four times over. The case uses USB-C so there are no proprietary cables to carry or lose.

Don't buy it if

You're after a new pair of earphones
Convenient in some scenarios they might be, but here’s a product that you’re only going to wear on sunny days, the frequency of which depends on where you live. Their short battery life also means you can’t reliably use them for an entire day. 

You must have bass
Although their clarity makes them usable for hands-free calls and for listening to podcasts and talk radio, the Spiro Transparent Brown’s micro speakers and woofers don’t muster enough bass response for music to impress.

Jamie Carter

Jamie is a freelance tech, travel and space journalist based in the UK. He’s been writing regularly for Techradar since it was launched in 2008 and also writes regularly for Forbes, The Telegraph, the South China Morning Post, Sky & Telescope and the Sky At Night magazine as well as other Future titles T3, Digital Camera World, All About Space and Space.com. He also edits two of his own websites, TravGear.com and WhenIsTheNextEclipse.com that reflect his obsession with travel gear and solar eclipse travel. He is the author of A Stargazing Program For Beginners (Springer, 2015),